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4/28/06 Help, my computer randomly restarts

by Lee Koo (ADMIN) CNET staff/forum admin / April 26, 2006 9:35 AM PDT

I have a Dell Dimension 4500 PC with a Pentium 4 2GHz processor. The computer has been randomly restarting.</b> It is not caused by using any one application, and it happens completely randomly; it doesn't matter if the computer has been on for 5 minutes or 3 hours. Also, the system clock is losing time (the time is always wrong and needs to be reset). I thought that the CMOS battery might be the problem, so I swapped it out for a new one, but there's been no change or improvement. Next, I thought it might be the power supply not having enough wattage (it is a 250W PSU). The PSU fan is barely blowing, and I thought it could be overheating. I haven't purchased a new PSU yet, because I'm not sure that is the problem. I have Norton AntiVirus 2006 installed, and a full system scan has not revealed any viruses. I have Windows XP SP2 and have all downloaded Fixes/Updates. The Microsoft Malware removal tool did not find anything either.

I bought this computer from a friend. She was not too discerning in her Internet usage and ended up having to reformat the hard drive and reinstall Windows XP due to viruses. Since then, I have utilized Ad-aware, antispyware, and Norton to clean up the computer. There are no more problems with the computer that point to viruses, other than this random system restarting and the system clock inaccuracy.

Submitted by: Derek B. of Chicago, Illinois



This doesn't sound like a software/malware issue. Given that you mentioned a format and reinstall of XP was part of what was done to the box when you got it, it's not generally likely that some malware might have survived, unless, of course, there's another partition on the hard drive that wasn't wiped out.

And while I (and most everyone else) considers Norton AV to be more or less useless, I can't recall any reports of it causing random reboots.

Just to be on the safe side, you may want to consult the Event Viewer to see if there are any clues in the logs as to why it's rebooting. Right-click on the My Computer icon and select Manage. This opens the Management Console. Switch to the Event Viewer and go through the three logs.

There IS one possibility, however, that can and quite frequently DID cause random reboots. About 3 or 4 yrs ago, there was a nasty virus that DID cause reboots - mostly while it was ATTEMPTING to gain access to a computer. The bugger was so badly written, when it tried to access and unprotected Windows machine via the Internet on RPC, it would often crash and reboot the PC being afflicted. The odds, however, are not good that this is your culprit. A good firewall should block these attacks and it hasn't been in circulation much lately.

Now then, let's look at the computer itself. The first thing that struck me was the power supply. 250 Watts for a Pentium 4 2.0 GHz chip and the rest of the system is MAJORLY WEAK!

Wimpy power supplies will cause problems if you're running any applications that require the CPU to work more than at idle. Also, if you've got a number of USB devices plugged into the computer, that also adds a drain to the already inadequate power supply. If memory serves me, those Intel P4 2 GHz chips were supposed to be paired with at least a 350+ W PSU. What was Dell thinking - besides the obvious (making profit)? Just to be on the safe side, you may want to consider replacing the PSU with one that's rated at least
400 Watts.

Another possible issue would be the CPU itself. Pentium 4 chips, especially of recent vintage, tend to run blazing hot. Heat + CPUs = BAD news. If something is not working on the cooling end - be it dust clogging a vent, a fan bearing gone bad and not spinning up to proper speed, etc..., it's a good bet there's bound to be problems.

To check this out, take note of where everything plugs into the back, then unplug everything and open the case. If you see a ton of dust bunnies in there, gently remove them with vacuum cleaner or a can of compressed air. Pay VERY close attention to any vents that are used for intake or exhaust of hot air going to or coming from the CPU, make sure the fan spins freely and isn't weighed down with a heavy layer of crud and make sure the heat sink is likewise cleaned out.

Once you've cleaned the box out, you might want to take a moment to look at the motherboard itself. Take a look at the capacitors - those are the small bits on the board that look somewhat like beer or soda cans. The tops of them should be slightly depressed on the top. Should you see they be bulging on the top, that may be a sign they've blown and are no longer any good. Depending on which ones and where they're located, these can cause problems similar to the ones you're experiencing. If this is the case - it's probably time for a new motherboard.

Many modern motherboards also support a "PC Health monitor" function. If you hit DEL (or F1 or F2 on some models) as you're booting and go into the BIOS, there may be an option to check the temp and how fast, if at all, the CPU fan is running. There may also be an auto-shutdown feature where the machine will shut itself off in the event the system gets to a certain temp. Check your owner's manual to see if this function is available.

If you don't have the PC health monitor feature, you will want to power up the computer while the case is open and check to make sure the fans are spinning up and pushing air. If they're not, then replace as needed.

As for the clock... Chances are the clock problems are caused by the frequent reboots - especially ones of this variety. As the CPU gets busy doing whatever task(s) it's got to do, it draws more power. When it gets to the max the power supply can put out, the available power drops and the motherboard reboots itself. This is a voltage spike... This can and usually does disrupt the clock. Fixing the power issue will fix the clock issue most of the time - unless the clock circuit's been damaged by the spikes. In which case, you'll probably need to activate Windows automatic time update function or get a 3rd party utility that keeps the clock synced with any number of atomic clocks around the world.

Submitted by: Pete Z.



Derek, there are a number of issues that could be causing this problem.

First, let me put your mind at ease regarding the slow power supply fan; Dell throttles the fan speed according to the temperature, in order to maintain a constant operating temp. They also do this with the CPU fan. A slow speed is not indicative of fan failure. The Dell failsafe mode is to run the fan at full speed, at which point your computer sounds like a Cessna preparing for takeoff. A really, really loud fan indicates that there's a problem with the temperature sensing circuitry; a quiet, but turning, fan is normal.

I'd be surprised if you have a virus or spyware issue; but to check, I would run an online virus scan. These really are the gold standard in verifying that there are no viruses on the machine; they won't remove them, but they will tell you whether or not you're infected, and with what, and at what location. I use the Norton online scan, as I feel it is the most comprehensive; but several other companies offer similar services. To scan for spyware I use Ad Aware, but again there are other products that are as good. I'd use Ad Aware to remove any spyware first, as the Norton online scan will find and flag - but not remove - the spyware.

The fact that the clock is constantly wrong and replacing the battery did not solve the problem, concerns me. I'm worried that you might have a motherboard with swollen capacitors. To troubleshoot the hardware I would power the machine down, unplug the power cord, and start by doing a close visual examination of all the capacitors on the motherboard. If you have any swollen capacitors, then you've identified the problem; and realistically it's time for a new motherboard, as the cost of removing and replacing the capacitors greatly exceeds the cost of a new motherboard. Capacitors should have an absolutely flat top and straight sides; they usually have an 'X' etched across the top. If the sides or the top are bulged, then you've got an answer - not a happy answer, but an answer. I mention this because many machines - not just Dell - dating from this time period had a problem with swollen capacitors.

Assuming there are no swollen caps, I'd then remove all non essential cards from the machine. This would include sound cards, TV cards, USB expansion cards, modems, and anything else that's in the PCI slots. The idea is to reduce the machine to the absolute minimum number of components that will still provide a (barely) functional computer. I would also remove all but one memory module, and disconnect the power and data lines from all but the primary hard drive. Of course, I'd also unplug any USB devices outside of the essentials. You should wind up with four cords connecting to the computer box; power cord, video cord, mouse, and keyboard. Everything else should be disconnected.

At this point, run the machine, and wait for it to crash. Hopefully, it's now stable. If it crashes, then I'd swap the remaining components in the machine - probably just the memory module and video card - for known good components. If it still crashes, then the problem is either the power supply unit or the motherboard; you could try swapping out the PSU for a known good unit, but my money is on the motherboard being the problem.

If the machine is now stable, then you need to add components back into the mix, one at a time, until you identify the culprit. Because the problem is random and can take hours to occur, this will be a long, drawn out procedure. When you add a card, it's important that you use it during the testing period; I once worked on a machine that had an internal DSL modem card that was just fine, until you hooked it up and surfed the web... at which point it would bluescreen windows 2000. The moral there is, don't just plug in the card and install the drivers; actually put it through its paces.

You may find that you have two components, either of which is fine on its own, but when used together causes the system to crash. This is why it's important that you use WHQL certified drivers for all peripheral components whenever possible. Windows XP will complain when you try to install a driver that doesn't have WHQL certification; whenever possible, use certified drivers.

Using this basic troubleshooting procedure - stripping the machine down to it's absolute minimal configuration, achieving stability, then adding components one at a time - is a useful method of identifying a defective component, and turning a troublesome machine into a useful one. I hope that you find this helpful, and that you wind up with a rock solid machine for many years to come!

Submitted by: Charles W.



The clock issue and the random rebooting are, in all likelihood, separate and unrelated issues. Let's deal with the potentially more serious issue first, the random rebooting.

Whenever a computer starts behaving erratically, one has to consider viruses, adware and spyware as likely culprits. By reformatting and scanning your drive with Norton AntiVirus and antispyware software, you took reasonable steps to rule out this possibility. However, if the culprit is spyware, it might have been bundled with a third-party software and thus reinstalled after you reformatted your hard drive. Also, because antispyware software is not nearly as good as its antivirus counterpart in identifying and removing offending agents, an undesirable entity might have evaded detection, or the scanning engine you used might have left active spyware components behind.

Taking into consideration the troubleshooting steps you have taken, as well as your concerns about a faulty power supply unit (PSU), it seems unlikely that malware is at the root of your problem. Still, you have to allow for the possibility, however small, that the rebooting issue and the PSU issue are also separate problems - in other words, that you are dealing with three separate issues, counting the inaccurate system clock. For the sake of thoroughness, it wouldn't hurt to check the following Knowledge Base article;en-us;894278

to see whether the random rebooting might be caused by the presence of a root kit. This is a simple way to rule out yet another causative agent before taking on more elaborated troubleshooting steps.

Now, the fact that you brought up the possibility of your PC overheating suggests that the PSU has been a source of concern for some time. It also points at an issue that needs to be addressed, whether or not it ultimately is the cause of the random rebooting.

The first thing you should do is to open the case of your Dimension and verify that all power cables are securely attached to their respective components. It is possible that when you opened your computer to replace the CMOS battery (or for any other thing, like adding a memory card), you might have accidentally pulled and loosened a power cable. A loose or otherwise damaged power cable would explain both the random rebooting and why the power supply unit fan is "barely blowing."

While you are at it, inspect the fans for heavy accumulation of dust, hair, or the presence of a foreign object obstructing the fan blades. Use a compressed gas product like Endust for Electronics Duster to gently blow off lint, dust, and other contaminants. Compressed gas dusters are available at most office and computer supply stores.

(Before working inside your computer, make sure you are properly grounded. Failure to do so might result in electrostatic damage to components. To learn more about necessary precautions, please visit the following Knowledge Base article:

If all power cables are secure and there is nothing physically obstructing the fans, you should disable Windows XP's Automatic Reboot. By default, Windows XP reboots whenever it encounters a system failure. Because of this, any error messages pointing at the cause of the failure may vanish before you get a chance to even realize they are there. To disable Automatic Reboot and see whether your operating system can pinpoint the problem, perform the following steps:

1. Right-click the My Computer icon (either on your desktop, in the Start menu, or within your Control Panel), then click Properties from the drop-down menu.
2. Once the System Properties window appears, click the Advanced tab, and then click the Settings button under Startup and Recovery.
3. The Startup and Recovery window appears.
4. In the System Failure section, remove the check from the box next to Automatically reboot, then click OK to return to the System Properties window.
5. Click OK to close the System Properties window. Restart your computer if prompted to do so.
If the random rebooting is being caused by a software conflict or a problem with your memory, Windows XP should now display an error message the next time the system crashes. Write down any error message exactly as it appears, and search the Windows XP Help and Support website

for more details as well as any known solution. If your issue is resolved, feel free to enable Automatic Reboot once again.

If you are unable to elicit any error messages, you should consider replacing the PSU as soon as possible, lest you end up with a costlier tragedy at hand. At this point, you might want to check Dell's Support webpage

and Dell's Community Forums

to find out whether other Dimension 4500 owners have encountered similar problems. If there was an issue with faulty PSUs (or memory chips, which can also cause this problem) in this particular line of Dell PCs, you might be able to get a free replacement even if your computer is no longer under warranty.

Ask your friend whether the computer is still covered by an extended warranty or service plan. This would be a good time to request a transfer of ownership, if you haven't done so already. That way, you'll be able to deal with Dell Support directly rather than through your friend. (Chances are the friendship will come to an abrupt end the first time you ask her to deal with Dell Support...) For more information on this subject, visit

If the issue persists even after replacing the power supply unit, you probably have a problem with your memory modules. Please refer to your computer's owner's manual and/or the Dell Support website for instructions on how to test your computer's memory.

As far as the loss of time in Windows XP, Dell Support document #RA1060115 discusses this issue and provides two possible solutions. The first involves downloading an installing a small utility called Time.exe to reset the time synchronization in your operating system. You can access this short article and the download link by visiting

I installed Time.exe several years ago, with mixed results. A better solution was installing a free utility called Rocket.Time that connects to atomic time servers in the Internet at intervals, and corrects your system clock as needed.

The latest version of this utility lacks the option to hide its taskbar icon. The interface is somewhat busier, too - an obvious attempt to encourage users to upgrade to the premium version of the software. Older versions with the hide icon option are still available, and you should be able to find one here:,fid,17628,00.asp

Rocket.Time is just one of many programs designed to keep your system clock accurate. It is simple, free, and doesn't use a lot of resources. If you would like advanced functions such as different time zones and alarms, you can upgrade to the paid version or look for other alternatives by visiting

and searching for "clock." But if all you need is something to keep your system clock accurate, you can't go wrong with Rocket.Time.

Good luck!

Submitted by: Miguel K. of Columbus, OH



Derek, this can be a hard problem to fix because it can be caused by just about anything in the computer, as well as software issues. So the approach is to go after the most common problems first. However, in your case you have reinstalled Windows and the problem happens randomly rather than with specific programs, so it is probably not a software issue.

The most likely cause of this, by far, is bad memory. The way to test memory is to download a self-booting memory test program, and the most respected programs are Memtest and Memtest86 (two now-different programs that evolved from a common root). You can find these at and They are free, and you can use either/both. Microsoft also actually has a very similar memory diagnostic that can be downloaded from the Microsoft web site.

To use these, note that the program that you download is not the actual test, but rather is a program that will make a self-booting test floppy diskette. After using the downloaded program to make this diskette, you reboot the system from the floppy. The program is self contained and does not run under any operating system, neither Windows nor even DOS. For systems without a floppy drive, a ?dot-ISO? file is also available to make a bootable CD. Once you have the CD, you can use it to run the test on a system without a floppy drive. The test needs to run for a number of passes (will probably take several hours or overnight) with zero errors. If you get any errors at all, even just one, you have bad memory in your system, which you need to replace. This is very common, and is the most common cause of such crashes.

[One additional thought here, I think I?d remove and reinstall (reseat) the memory modules before running the test. They may simply have worked lose or be making bad contact with the memory sockets.]

The next most common problem is the power supply. In a ?generic? system, I?d just suggest replacing the power supply, but you have a Dell system, which may use a proprietary power supply for which a replacement is available only from Dell (and given the age of the system, maybe not even from Dell). If a generic ATX standard power supply will fit, try one. However the cheap power supplies that come with cheap cases (and almost any power supply selling for less than about $30) are often pretty junky. Go for a quality replacement power supply, 350 watts or more, by Enermax, Acer, Antec, Thermatake, CoolerMaster or other good brands. A quality 350 watt supply will easily be more stable and reliable than a cheap 400 or 500 watt supply. You can almost judge the quality of a power supply by it?s weight and by looking at the size of the capacitors, transformers and heat sinks, visible through the fan openings.

Now I?m going to get ?edgy?, and this isn?t for everyone, but power supply problems and random lockups are often caused by dust and dirt that have accumulated over the years. If you want to be aggressive, remove the power supply and let it sit for a day or two so that the capacitors have discharged. Open the power supply carefully, and use a can of compressed air and a ?? paint brush to carefully clean (dust) the interior components. Reassemble. Don?t do any more disassembly than necessary, and don?t touch anything inside the supply except with compressed air and, if necessary, the brush bristles (usually compressed air alone is enough). This is not for everyone, but in a supply that is several years old the amount of dust can be staggering and can cause the type of problems that you are experiencing. With a proprietary unit where a replacement is either expensive or unavailable, sometimes you have to resort to disassembly / cleaning / repair rather than replacement.

[You mentioned that the power supply fan was running slow; this may either be normal, or it may be the problem: some power supplies have thermally controlled fans that are supposed to run slowly [=quiet] until and unless a thermal sensor becomes warm. But the sensor may not be sensing a part of the power supply that is overheating. Regardless, however, replacing just the fan inside a power supply, while possible, involves more issues than I can reasonably discuss here.]

There is a similar dust/dirt issue in the area of the CPU heatsink and CPU fan (if there is a separate CPU fan), and the solution there is basically the same type of cleaning with compressed air and possibly a brush. It?s also possible that remounting the CPU with new thermal compound would help, however, most inexperienced users will cause more problems than they will solve if they attempt this. Cleaning the CPU heatsink and fan is usually all that is required. Not all Dell systems have a dedicated CPU fan, but fans do fail, as well as get hopelessly clogged with dust, so investigate that. A can of compressed air will usually work wonders.

While you are at it with the compressed air, blow out dust from the rest of the system, paying particular attention to the CPU chipset on the motherboard and, if there is one, it?s heatsink.

If these suggestions don?t fix the problem, you are into a situation that becomes far more difficult to fix and that may not be economically repairable. The next most common problem is the motherboard, but there is no good way for an end-user to diagnose this other than by substitution. Plug-in cards (video, sound card, modem, LAN) can cause crashes, and even IDE drives on occasion. And, finally, although it?s rare (very rare, really) it could be a bad CPU. But memory is about 70% of these problems that are caused by hardware, and the power supply and cooling issues are most of the rest, so start there. One final comment, if the system is ?overclocked? in any way, revert all of the settings and jumpers to their default positions. But with OEM systems like Dell, overclocking usually isn?t possible anyway as it is with a home-built system and a retail motherboard.

Good luck, this should get you started in the right direction.

Submitted by: Barry W. of North Canton, OH
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by Lee Koo (ADMIN) CNET staff/forum admin / April 26, 2006 9:35 AM PDT

I have seen this problem on a few computers with three different hardware causes:
1) The problem might be a disconnected or failed fan on the computer.
2) The problem might be faulty RAM that has use or heat issues.
3) The problem might be an underpowered/failing power supply unit.

All of these above problems can became more pronounced when the computer had been running for a while or when the room was hot. The RAM issue can sometime become more pronounced as you load more or larger programs into memory and then use a new memory location.

To diagnose the first problem, fan issues, a quick visual inspection of the computer's fans with the computer case open is all it takes. If the CPU or case fan is disconnected, power off the PC and reconnect the computer power to the fan. If the fan still fails to function when the computer is warmed up, replace the fan. If the power supply's internal fan has failed, replace the power supply.

To diagnose the second problem, faulty memory chips, power off the computer and remove the RAM sticks. If the contacts on the RAM look discolored, carefully clean them using an eraser. Carefully replace the RAM sticks back into the computer. (Look for the notch(es) in the RAM to make sure that you place it facing the correct direction in memory slots.) Visually and using a finger as a straight edge inspect the seated RAM sticks for horizontal alignment. This makes sure the RAM is inserted fully into each slot. Power on the computer and download a free memory check utility from the Internet. (I've successfully used Memtest86 and others.) Follow the program's directions for installation and use. The memory checker utility should give you an option to run it from once to a continuous loop. Choose to let the program run a long test loop and then come back and check it in the morning for errors. If it finds an error, purchase and replace the faulty RAM stick. Next, run the memory check utility program again. Once computer's memory passes the memory testing, you can continue to use the computer normally.

To diagnose the third problem, the power supply, takes a bit more investigation. Power down your PC and remove any unneeded add-in cards and then power on your computer to see if the reboot problem reoccurs when you start to use it. If your computer is not running with an built-in video from the computer's motherboard but is using an added video card, this video card is likely to contribute to the problem. Powerful video cards tend to draw lots of power and can overtax a failing or low current power supply. Additional or larger hard drives are also common contributors to a power instability issues.

The only solution for power supply issues, short of permanently removing power drawing hardware, is to replace the Dell's OEM 250 watts power supply with a more powerful "ATX style" power supply. I would look for at least a 350 watt power supply from a name brand company such as Antec, PC Power and Cooling, Thermaltake, Coolmax, etc. A quick Google search can give you lots of power supply reviews and replacement tips.

Good luck!

Submitted by: Steve H. of Beaverton, OR



I think that the most important information to be gleaned from the writers question is that the machine was badly infected, wiped and had the system restored. This tells us that it had viruses or worms but it doesn't tell us what kind of infection. Some of the old Trojans / worms, used to cause exactly the described behavior. How was the drive wiped? What if the worm resided in the boot sector and was never removed? In a badly infected machine that does not seem to improve after being reformatted, I recommend a low level scan, resetting all of the drive's sectors back to zero. It is the only true way to clean a drive. I once had a drive that caused a motherboard to fail after being used for a couple of weeks. I could
never truly clean the drive. I have built three other systems with exactly the same parts but without the board failures. Only the change of motherboard type, same manufacturer, solved the problem.

Another trick I like to use is to download and install AVG for free on the infected machine after having disabled Norton. I then use a full system scan with AVG. This has found many viruses which the infected Norton has not. I have had to do this several times recently on customer's machines.

It would seem that the writer has also made a fatal assumption. I would consider that her friend was not really computer savvy. I assume this based on her letting her machine get so very infected. I would not assume that she installed either the latest or even correct drivers for the system. Sometimes, proprietary machine makers have different hardware for machines with the same model number. Perhaps those drivers installed on the reformat were not the correct ones. Also, since the writer is using SP2, the machine might not have the updated SP2 drivers. The clock problem might very well be just a bad chip on the board or again a deeply seeded virus.

In summary, the problem is most likely either an infection or driver problem. I would search out the manufacturer's knowledge base for driver queries on the same issue or just bite the bullet and do a full low level scan and reformat. In the end, the time wasted searching out rare and obscure problems can be better spent enjoying the computer, once it is wiped properly.

Submitted by: Thomas P.



Hi Derek. Random restarts are a problem that has several likely causes, so the search may take you a while.

1) spyware
2) computer has been overclocked
3) memory unseated or partially seated
4) bad memory stick (or mis-matched memory)
5) system overheating
6) case shorting somewhere

Easiest: Run Adaware and Spybot (both available free) to rule out malware. Second easiest - look into your bios and make sure that the CPU is running at the right speed. Overclocking (or wrong-clocking) can cause both of the problems you describe.

Then reseat all your memory sticks. If that does not help, try using different ram sticks - and make sure they match. It would be odd if a Dell had this problem, but maybe it was upgraded locally. Or maybe one has gone bad.

If the system is overheating, the restarts might still seem random. Your heating/AC might change the external temps enough to make a difference. You should carefully measure the CPU temperature which should not be above 40 degrees C. If it is, check for dust, dirt, anything blocking the fan. If none of this helps, try running it with the case open and see if it makes a difference.

If nothing there you can start the real treasure hunt - looking for a crimped or cut wire, spider web or anything else that could be shorting to the case. The ultimate tough job is removing the mobo and looking for a screw that fell under it and is causing a short.

And the system clock inaccuracy - if not clock speed, I'm betting on a memory problem. I never figured out specifically why it happened, but my clock problem went away after I fixed my memory problem.

With good luck, you will find it long before the wire/case search. Hope this helps.

Submitted by: Merry S.



Hi Derek,

Sounds like a few possibilities to me....either the PS may be failing, you have one (or more) bad memory modules, your CPU cooling fan could be starting to fail, or you installed too many add-ons to the computer (new video card, CD/DVD drives, other PCI cards) and the power supply can't keep up.

If you purchase a new power supply for the computer I would make sure you buy a Dell power supply, or be absolutely sure that your version of the Dimension motherboard is a true *Standard ATX* type motherboard, and not one of Dell's "modified" (/ie. proprietary/) ATX boards. I don't know if things have changed much for them since the early Pentium I ? II days, but Dell used to use non-standard "ATX-style" connections. This means you could take any standard ATX connector ( on a standard power supply) and plug it into the non-standard Dell ATX header on the motherboard, or visa-versa, and it would totally fit. The unfortunate part came when you powered the computer on and <poof>...smoke, sparks, nothing.

Congratulations, you just fried your motherboard....and Dell doesn't care. Dell would re-wire their ATX connectors, example...12V where ground should be; -5V where +5 should be, and so on and so on. Big reason why I'm not a Dell fan, or any other name-brand computer fan, for that matter.

That said, here's the list of things I would do if troubleshooting your computer (in this order):

* Look inside the tower for signs of anything shorting, loose
connections, or dirt/dust build up. Definitely check the Clear
CMOS jumper on the moboard and verify that nothing is making
contact with it. Also, be sure to check that the clips to the
memory sticks are secure. If there is a lot of dust built up on
the fans or fan covers, then clean them with something like Tech
Duster, or whatever.

* Power on the computer and enter BIOS to have a look at a section
called System Monitor (or something to that effect) to check
voltages. It's typically the area in new BIOS' that list voltages
and CPU frequencies. You really want to leave the computer on for
a couple of minutes to get everything warmed up inside and watch
for any unusual fluctuations, like plus or minus 1V on the signal
lines. If you see any of the readings bouncing all over the
place, chances are the power supply is starting to fail and
creating "noise". Noise in DC voltage lines is bad news for data.

* While in BIOS check the CPU temp. Pentiums seem to run a little
cooler than AMDs chips so I would be wary of anything 50C and
above with the machine just sitting there displaying CMOS. Maybe
the CPU is going, maybe the fan is going. Replace fan(s).

* If the BIOS PS voltages look relatively stable, and the CPU temp
isn't too terribly hot, then download and run a program called
Memtest86+. It's a free diagnostic program that can be loaded to
either a boot floppy or boot CD (I prefer floppies still,
personally). Install the program, reboot with disk in the drive
(make sure the hard drive isn't set to boot in BIOS) and basically
leave the computer running for 24 hours at least. What this
program does is run a battery of memory tests over and over
again. The idea being to tax the system, heat it up, and flush
out any failures. Any errors that the program finds will be
listed in red. Memtest86+ also makes for a good burn-in program
after you build a brand new PC. Microsoft has a similar program
for free from their website, just search for "memory diagnostic".
I think it's called Windows Diagnostic, or something to that
effect. Any errors you find mean one, or more, of the memory
sticks is possibly on the fritz. If you have multiple sticks
start switching them out, and in different configurations and
re-run the program. If you have only 1 stick, replace it with new
memory and re-run the program.

I'm leaning toward the PS being the culprit. I hope it's not, considering you'd probably pay double for a Dell PS than a standard ATX one of similar power. The rebooting and system clock thing just sounds a little too weird to be strictly memory problems. I've heard there are weird viruses that can damage BIOS, but I have yet to come across any.....and I think it's bunk, personally.

Good luck with your investigation.

Submitted by: Tony M.



I see your PC keeps randomly restarting and you can't tell exactly why. I also see you suspect it may be your power supply, and you probably are right. I will examine what you say and tell you an overall conclusion from my own experience and things I've heard from others.

If your computer keeps restarting like this, there is only two possibilities, a program is causing it, or it is a hardware problem. You say it isn't any application, but it could be one of the most secured processes that you don't know about. Is automatic updating turned on? If so, maybe your PC is downloading updates that need it to be restarted. But lets rule that out since you would probably have found out. You also say you have anti-spyware, anti-virus and ad-ware removers, so you can't have any of those. The problem now leads us to hardware.

Problems with the processor, memory and video card are discarded, since they would either give you a blue screen, or simply the computer wouldn't be able to boot. That leaves us with a faulty power supply and problems with the 'time'. As time goes by, power supplies can only take so much abuse and they start to degrade. Before they burn and become completely damaged, usually the fans start to fail first. Considering you have a Pentium 4 processor built around 2002, you are left with a processor that runs hotter and consumes far more power than the latest Pentium 4s despite their higher speeds. These days 300 watt is standard for a PC like yours, but 350 watt or 400 are recommended. Dell probably didn't know about this at the time they built the system, but your system is not powered with enough energy, and at first when you turn on the computer, the power use and the heat is minimal, but the longer the computer stays on, with more programs running at once (even if they are simple programs like Internet Explorer or Microsoft Word with maybe Windows Media Player in the background) the faster your power supply will heat up and need the fan to cool it down, but since the fan has taken more abuse than it could handle, it doesn't get its job done anymore, and therefore your PC is forced to either restart or turn off instantly, which may later on cause errors, to prevent your power supply from burning or any other of your hardware from becoming damaged. I would recommend you contact Dell about what power supply is best to upgrade your system. Remember to get at least a 350 watt one, or 400 if you will be doing some gaming, since gaming is the best PC over heater.

As for the problem with time, it probably is related to the settings in "Date and Time" properties. To check if that is the case, double click the time on the taskbar, then click the "Internet Time" tab, and uncheck the "Automatically synchronize with an internet time server" option. If you want it to be synchronized then choose the right time zone under the "Time Zone" tab, and make sure to choose if you want automatic daylight saving by checking or unchecking the option on that tab. I assume this may be the fix to the problem, since you didn't say it also loses the date, which if it did, would mean then that your Battery connector is damaged. I hope these methods solve your problems and you can have everything fixed as soon as possible.

Submitted by: Israel L.



Although I believe the answer to your problem may be a simple one, let's go over a few troubleshooting steps. I believe the most likely cause for this issue is external to the PC, most likely a bad power strip. It could also be with the actual power outlet where it is plugged in. I would first try another power strip, or possibly a UPS (battery backup). You can usually find a 325VA or 350VA model at Best Buy or CompUSA for under $40, and these are fine for a single PC. If the power outlet or the power strip has a "brown-out" (where the power drops below normal levels, usually about 97 volts), or if the power strip has a bad fuse, they could cause the power in the PC to cycle and could also cause the CMOS clock to reset.

The power supply inside the PC is a possible culprit. If it is overheating, when you put your hand behind it it should feel hot (not just a little warm). Most low end power supplies don't have a very powerful fan, so as long as the fan is still spinning and is not making noise it is probably OK. A 250W power supply should be enough for that PC, unless you are running a higher end video card or sound card, or if you have a large number of USB devices. If that is the case, it might be worth investing in a 350W or higher power supply. There could also be a short inside the power supply, if no other troubleshooting steps fix the issue, I would try replacing the power supply.

To eliminate the possibly of a virus, I would try a second scanning method. One virus scan that I like to use is Computer Associates online scan. Logon to and click on "Scan for Viruses" towards the middle of the page on the right. You will need to use Internet Explorer, and you will have to allow the ActiveX control to load by clicking on the Information Bar at the top of the window. After the control installs, it will download several virus definition files. When they are finished, select all of your hard drives (indicated by "Local Disk") by check the box next to them and then click "Start Scan" on the right. This scanner has helped me find viruses that Norton has missed.

If none of these steps help, the problem may unfortunately be with the motherboard itself. If you are familiar (and comfortable) with flashing the BIOS, that would definitely be worth a try, but you might need to replace the motherboard or the PC itself.

I hope these suggestions help (and I hope it was just a power strip!).

Submitted by: Dean L. of Colorado Springs, CO



Hi Derek,

Looking over your problems. I thought one of four things:
Damaged hard drive,
Poor settings on your BIOS (you should check that first before messing with the CMOS)
Power supply

I'm guessing you aren't a computer guru type or you wouldn't have asked the question. Yet you seem to have a decent understanding of computers, and had no trouble going inside the case and replacing your CMOS battery. So I'm going with answers that should be easy for you to work with - not so simple for those less experienced than yourself - to make this as easy as possible.

Your motherboard regulates your power supply as to what goes where and, though rare, Motherboard electronics can be damaged if hooked up to a cheap and wonky power supply.

But let's start with the hard drive first. For a fact, you could spend days and even weeks trying to debug your hard drive, and in the end, it is possible that you can fix your problem. Just as possible is you could waste the next few days and even weeks working on an unsolvable problem. If you are like most people, time is money - or time is family, losing money or family time to a buggy computer is no fun so,

As a computer tech, I advise all of my friends and clients that, when buying a used computer, regardless of who you purchase from, Get A New Hard Drive. A new hard drive for your used computer is all good with no minuses.

Hard drives are incredibly inexpensive. You can get an excellent, high speed hard drive - with warranty - for under $100.00 in the U.S.

Any technology, in hard drives, that you purchase today will be better than anything that is even one year old.

Your new hard drive has no bad unknowns such as possible viruses, trojans, spyware, and such.

The installation of all of your software is clean!

And then you'll have a working hard drive. The majority of computer problems stem from faulty hard drives damaged by viruses and other ills. If you still have problems, you've at least eliminated the most likely source, plus you'll know that your old hard drive is good and you can wipe it and use it as a second hard drive for back up - which is always good.

Then your option would be your BIOS - which you should update only IF updates are available (See the computer or motherboard manufacturer's site for updates) Your power supply - which would have to be replaced (NEVER try to fix your computer's power supply), Or your motherboard improperly regulating your power supply - which would require the replacement of your motherboard.

Good luck!

Submitted by: E. C. M.



Random restarting of a computer can happen for many reasons. Sometimes it's software, sometimes it's hardware, and sometimes it can be cooling, as for the PSU it is highly unlikely to be your PSU with the exception of cooling.

There are a few things you can check, firstly check for viruses and malware which you've done already. I notice though you put that you only tested with Microsoft Malware remover and Norton Anti-Virus. You might want to do a double check with another antivirus and malware remover, like HiJack This, AVG Anti-Virus Free or Lavasoft Ad-Aware, just in case your current Anti-virus program is missing a particular virus. This happened to my friend a few years ago with Chernobyl, Chernobyl was infecting and McAfee ignored it because is a vital system file and it couldn't do anything about it, but Norton Anti-Virus warned us that the virus was there but couldn't remove it, so we at least knew it meant a full system re-install, rather than sat around wondering where this virus kept coming in from! So it's always best to get a second opinion from another anti-virus software (usually just try a free one rather than going out and buying another one)

Next thing to check is the cooling of the system. Sometimes it can be the CPU is getting too hot, or the PSU could be getting too hot. One really important thing to check is that the fan on the PSU is definitely spinning around. If it's not it won?t be too long at all before it goes bang. If the fan on the CPU isn't spinning around and you notice the PSU is getting very warm (similar to radiator heat), seriously consider a new PSU before it overheats and destroys the entire computer. I've had one do that to me and it took out the motherboard and video card too.

Now as for the CPU overheating. Usually when a CPU overheats you won?t notice anything from the outside, except the computer might crash a lot and sometimes do random resets where it just goes to a black screen and about a second later it comes back on and starts re-booting. The time to re-boot will depend on the amount that either you or Windows is using the CPU, it could be 5 minutes, it could be 3 hours (it's usually less when using high powered programs like 3D games and CAD programs). One way to check to see if the CPU is overheating is to go into the BIOS when the computer resets (this can be accessed usually by pressing either ESC, F1 or Delete when booting, on most BIOS's it will have a message at the bottom as to how to do this, if it's got a flash screen with Dell on it when it first boots up try pressing F2 to hide that so you can see the message)

When in the BIOS it should show you information about your computer, like available RAM etc, also in that list it should list current CPU temperature. This is probably best below 35 degrees Celsius, certainly no higher than 40. If it is higher than 40 then it is a cooling problem causing these random resets. Check all the fans are rotating properly in the system, especially the CPU fan, check also you have a good airflow going through the system, cold air should be going in from one fan (usually the side fan) and going out through another fan (usually the PSU fan) to create a air stream over the CPU and other components to
keep everything cool.

Finally if this doesn't solve it, it is either going to be a software problem with Windows and could need Windows re-installing or a hardware problem.

To check whether it is a software problem in Windows is quite easy. Go and find a version of Linux that runs from CD (like Puppy Linux), boot into Linux and keep the computer going in Linux for a few hours, if after a few hours the system still hasn't reset, you know that it's most probably time to dig out the Windows installation discs and get re-installing, but if it has reset in Linux then it is a hardware problem.

If it is hardware then you're best to check all the wires in the computer are securely connected, especially the front connectors like the power button.

Good luck in solving the problem.

Submitted by: Darren F.



It sounds to me like Derek has a worm that is keeping his processor running 100% most of the time which precludes his clock from being updated. The one I found in my computer a year or so ago also kept me from any update or antivirus sites. Nothing I had, including the programs he mentioned and several more, could find anything wrong. The way I found it was to go to task manager and see how much my processor was running. It was 100% most of the time and a service host was doing most of that. I couldn't select the service host in the list of services because if I clicked on it, it would instantly move somewhere else. I searched the registry for anything running as a service and finally found this file running from a folder which did not exist under windows folder. I tried un-hiding everything with no luck. Finally I ran cmd and did a "Dir" in the windows directory and found the folder. Inside the folder were three files, one of which was xxxxhide.exe, xxxx being the name of the folder which I don't remember. I had to boot up in command mode to access the folder and, with the assign command, make it non-read only to be able to delete it. After that my problem went away and has not come back.

I just remembered that this worm would create a folder in the root called shopping and would fill it with several files and advertising pictures which it occasionally would pop up on the screen as programs were loading. I found that first, but every time I deleted the folder, within one minute the folder and all the files would re-appear. Obviously by the service host running all time. That drove me nuts for weeks until I found the fix above.

Hope this helps.

Submitted by: Glenn S. of Muscle Shoals, Alabama



One can only speak from experience on this issue. In today's world a 250 watt power supply is somewhat lacking I would suggest nothing less than 350 watt. It really depends on how many drives and fans the computer is equipped with. Next, local power suppliers and utilities around the country are often guilty of 'switching' glitches when changes to the local power grid load for the area are implemented. If the computer BIOS is set to auto-restart following a momentary power glitch, shut down or 'brown-out,' this could very well be what is causing the symptoms described. This is suspect if the events occur around the same general times daily. Loose power plugs, power bars and receptacles should be checked. All internal plugs and connectors should be checked also for a secure connection.

Another possible cause of system instability in my experience servicing hundreds of defective machines over the past 15 years, is the problem of CPU overheating caused by the accumulation of dust and debris in the CPU heatsink, drawn in by the cooling fan. This can accumulate, blocking the flow of air and hence the resultant CPU overheating and instability, careful removal of the fan, and vacuuming away the debris with the aid of a 1" paintbrush will clean up this mess. This problem is by no means confined to just the CPU fan. The same applies to video card fans and 'northbrige' chips. Also, all of these chips usually have a heat transfer paste, compound or tape sandwiched between the chip and its heatsink in order to 'bond' them together thermally. After time, these pastes and tapes tend to dry out. Any force or pressure applied to move or lift the heatsink will break this 'bond' degrading the efficiency of the heatsink to keep the chip cool. This again can cause heat induced instability, resulting in random shutdowns and restarts. Having a knowledgeable technician restore the thermal paste or tape could fix that problem.

The same sort of instability and random shutdowns can occur if attempts are made to overclock a system beyond its limitations. Speed freaks and those attempting to push their systems to the limits, often experience random crashes as a result of 'playing' around and trying to squeeze the last ounce of performance out of a machine. In my opinion not a sensible thing to do. Replacement of parts destroyed by this practice can be very expensive.
The other possibility, based on the incorrect clock needing to be reset constantly, to me would indicate a suspect motherboard or BIOS chip. Neither of these can be readily tested by the user and should be sent to the manufacturer for proper testing and checkout. If still in warranty, an RMA should be requested from the machine's manufacturer.

Another possibility could be a computer used in an extremely humid environment, excess humidity along with dust and debris inside the machine could cause more than just random restarts. I advocate 6 month internal cleanups for all computers exposed to humidity, tobacco smoke, house dust, airborn cooking grease, pet dander and coffee spills.

Last but not least, have your machine examined by a competent electronics technician, don't try to fix something yourself if you don't know what you are doing.

Submitted by: Robert F.




1) Since your friend has (probably) formatted the drive and reloaded the operating system, you won't have the Accessory program which displays your Dell SvcTag and Express Service Code. Also, you won't be able to use the website utility at to "Find my Service Tag." So, you should get a flashlight and write those codes on a piece of paper if you haven't already. When you next visit the Dell support site, create a login for yourself and put your computer into "My Systems & Peripherals" so you will always have it handy for future visits (even when using other computers to access the site).

2) Dell PSUs are equipped with fairly quiet fans (newer models, like yours) and I have changed fans only to discover the fan was just "like that." Turn the computer completely off and try to find a quiet time (radios and tvs off, your roommate not practicing on his drums, etc.). Find a way to hold one hand behind the PSU and listen and feel as you turn the power on. Typically, you will hear the fan "rush" as it spins up and you will feel a healthy flow of air almost immediately; then, within a second or two, the sound and the airflow will diminish. That is normal.


1) Try searching for others who have had this problem. I used Google Advanced Search, but you could use your favorite search engine and search for "computer reboots at random" (be sure to include the quotation marks). One rather interesting "hit" I got was where the first answer to the question was a "me too!" from a reader. Both were able to stop the problem by changing settings for their sound cards (which sounds bizarre to me, but Windows is a bit bizarre anyway, most would agree).

2) Try visiting Dell's website and using the "interactive" troubleshooter. Make sure the system "I need help with my:" shows Dimension 4500 and then click on "Start the Support Wizard" I have had pretty good luck with that on a few occasions, but not every problem can be covered. "Your mileage may vary."

3) I don't know what antivirus (AV) you are using, but I find many strange problems related to failure to maintain AV properly. Whenever I get a "new" (to me) computer, I get rid of the AV software without scanning or updating or doing anything else. Then I install my favorite AV (using a 30-day free trial if necessary) and let it run a full scan (which it does by default during installation). The AV is "e-Trust EZ Antivirus" and I have several reasons for preferring it to all others. You can be spared hearing the reasons. Happy (except for the most important one: e-Trust EZ Antivirus will install on an infected machine and remove problems "on the fly." Others will not do that!)

4) The problem could actually be a failing hard drive, and you might just get a new drive and install it and see what happens. Most likely your Dimension 4500 came with a 5400 rpm drive (since people tend to buy capacity rather than performance when selecting drives from Dell's website), and you'd get a performance kick with a 7200 rpm drive and probably get one for not much moo-lah.

5) The problem could also be failing memory.

6) If you have the Dell Diagnostics CD, or if through some merciful turn of events your friend didn't wipe the Diagnostics Partition during the Windows reinstall, you can run Diagnostics and perhaps let your computer tell you what is wrong. Tap F12 repeatedly during a reboot and select "Boot to Diagnostics partition". If it can't find it, that is tough noogies; you'll need the CD or download the diagnostics from for your specific model.

I am sorry you are having the problem, and I'm sorry someone has "reinstalled Windows" on your machine. Despite all the folklore, that is almost never necessary. One of my proudest moments was when my daughter reported that a "tech support agent" for a major manufacturer told her she must reinstall Windows. She said, "My dad would kill me if I did that without talking to him." She was right! She and I did a little troubleshooting over the phone and decided the best thing for her to do was to get whatever was holding her left Ctrl key down out of the keyboard or, failing that, buy a new keyboard. Grin

Even if you use the Dell supplied re-installation CDs to reinstall Windows, it will never be the same as when you saw "Starting your Dell computer for the first time" End User License Agreement, blah, blah, blah.

Submitted by: Chuck M.



I have several possibilities which might cause the problem.

Since Pentium 4 processors cause a lot of heat, you might want to check your processor temperature first. If the processor gets hot, try replacing the CPU fan. This won't be too expensive, but think about putting thermal paste between the CPU and the fan.

Another cause might be a failure of your RAM, even if you don't get blue screen messages. Try to execute a memory test (such as Memtest) to see if you don't get error messages. If this is the case, swap the RAM.

If the problem persists, I am afraid you're encountering a problem with your mainboard. You didn't state if the CMOS clock is still resetting after you changed the CMOS battery. If this is the case, SWAP THE MAINBAORD FIRST !

If you didn't add new extension cards (such as vid card), I don't think the PSU causes the problem. Generally, the system doesn't pass POST routine if this is the case. Moreover, since you experience the problem with the CMOS time setting, I think this is out of the question. However, if you added a videocard (Radeon 95xx, or GeForce FX) you're PSU is definitely insufficient (go for 400W PSU minimum).

Submitted by: Ron H.
Collapse -
If he did have a virus
by assina / April 27, 2006 6:37 PM PDT
In reply to: Honorable mentions

I found the only way to get rid of a virus or trojan was to start the computer with any normal DOS Start up disk, then run the fdisk command with the following "FDISK /MBR"
That has been getting any virus or trojan

Collapse -
Power Supply Should have made the cut
by rmcferren / April 27, 2006 7:28 PM PDT
In reply to: Honorable mentions

I'm sorry, as a service tech, I always check out the power supply in cases like these. This is especally true with name-brand systems as CHEAP power supplies are used almost exclusivly.

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My Friend had every one of the puters he used do this???????
by mobymik / May 1, 2006 6:57 AM PDT
In reply to: Honorable mentions

OK OK OK Matt is a young man who having lots of cool friends in high school and after that had multi-uses for the net- surfing, school, music, girlies and cars. His first puter was a Celeron E-Machines that would turn it self on and could not be shut down unless you shut off the power strip. I never solved the problem, I did everything too, software,hardware,scanning cursing,blah ,blah. So his mommy bought him a HP- P3. So no one can touch the new puter cause they might make it sick, right!! Well it only took a couple of months for my phone to ring and guess what? The same thing is going on, Say!! I can't believe what I'm hearing, so I go over to his house and sure enough the puter turns itself back on after you turn off the power , and the only way to shut down is to kill the power strip. I also did the industrial hip-hop to the puter too. Now I'm not going to fix either one cause I ordered him a Dell P4 white box and so far 3 months later he is ok. The only thing I can think of is his uncle Bill comes over and uses his machine from down south, and both times they said the puter changed their personalitys. Now this puter is off limits to Uncle Bill. So what am I trying to say? Well how about a puter show-- down on a TV show?? I have both of these units and they are still screwed up. hey are both available to buy if you are interested. If you think you have what it takes I can make these two puters come clean, I have them and they are still in rare form. I guess CNET could email me and We could hook up OK DEAL OR NO DEAL kind of action ya know what I mean. Mobymik the Vinman at your service!!!!!!!

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Other advice from our members
by Lee Koo (ADMIN) CNET staff/forum admin / April 26, 2006 9:36 AM PDT

I also have a Dell 4500 Dimension that had a unique problem that stumped me for days until i found a product named Xoftspy at In most cases where a computer restarts itself, it is usually caused by a virus that is hidden in a windows folder or the registry itself. In my case i was on the internet and when i got through surfing, i noticed that my desktop had a background theme that i did not put there. I could even open the themes tab in display and it was not listed. I ran across Xoft and ran a free scan and my problem showed up as the theme name with an html extension which was hiding in the windows system 32 folder. I turned off the system restore and went to the location file and deleted this theme and emptied the recycle bin. Then i rebooted the computer, and to my surprise- my desktop not only was back to normal, but the other background themes were now working if i wanted to use them. I strongly believe that there is a virus, possibly a trojan on your system. If AVG home edition and McAvee does not pick it up, it is cleverly hid and may not show itself so easily. Xoftspy is the only software that was thorough enough to find my problem. This software will scan for free but will not remove the listings, but you can make a note of the listings and manually delete them yourself because it gives their locations. If you choose to buy the software then you can use it to delete for you as well as restore any deleted files. After everything is back to normal you can safely turn system restore back on and there will not be an image file of the virus on your computer. I hope this helps.

Submitted by: Richard B.



When you mention that your PC clock is losing time, etc... that makes me think that there is an actual Dell-produced Time Loss patch that will fix it. For my Dell it was called tsreset.bat.

I would suggest going to, download & SAVE all pertinent patches & fixes for your specific model. Then copy all of those onto a CD for helping you with any future problems.

You may end up having to re-format your drive, but at least you will have all the necessary drivers ready. Also pay particular attention to loading these patch drivers in the proper order, like right after installing WindowsXP...before up-dating it to SP2. Hope that helps you.

Good luck.

Submitted by: Bob M.



This will be a short answer - and it may not get you all the way there, but there are too many
possibilities at this point.

My only recommendation is to bring up Windows in safe mode and let it run for up to 24 hours - or however long you feel is enough to prove that the problem is not happening any more.

The clock should still work in safe mode, so keep an eye on that too.

If both problems continue to happen, this is a h/w problem and you will need h/w diagnostics to debug it.

If neither problems continue to occur, then this may still be a s/w or application problem.

Submitted by: Mike D.



bring up the task manager and look under the "processes" tab for any unknown applications running....if unsure, "google" the processes name (i.e IF "explorer.exe" was unknown, you'd google "explorer.exe" but that?s known) if no processes look suspicious, and even if one or two are unknown or reported as bad, continue on.. try going to start> run> "msconfig" and scanning through the "startup" tab for any unknown, unneeded programs and applications, for it very well may be a corrupted but still runnable program (norton is known sometimes for its weird interaction with windows xp) or it may be damaged hardware, a corrupted os install you may be in need of a new "psu" as you call it for the power supplies I?ve been around only stay in perfectly working condition for a few years and if its a 64 bit system there?s a whole host of new sources for the problems....but alas, the only surefire way to alleviate your issues is to check your "psu" also check your CPU temp my notebook consistently shuts off due to overheating i don?t really have as much time to think out the solution as id like but seeing as I?ve dealt with this issue before in my work, its a rather random solution to a rather "random" problem.....never buy a pc used and expect to not change some parts as some pc parts do wear out over time

Submitted by: Nathan M.



1) Close all programs before running a HJT (hijackthis) log. I can't emphasize this enough. HJT, AdAware, Spybot and CWShredder cannot clean your system if internet browsers are open.

So please close all programs. You can leave your virusscanner autoprotect/shield, firewall, Spybot resident, popup stopper and the like open/running. But close Windows Explorer, MS Word, Notepad, AIM, games, MS Messenger, internet connections, telnet apps, and especially internet browsers (Mozilla, Internet Explorer, Netscape).
2) Download Ad-aware SE <> Install the program & launch it.

First, in the main window, look in the bottom right corner and click on Check for updates now and download the latest reference files.

Next, we need to configure Ad-aware for a full scan.

Click on the Gear icon (second from the left) to access the preferences/settings window

1. In the General window make sure the following are selected:
? Automatically save log-file
? Automatically quarantine objects prior to removal
? Safe Mode (always request confirmation)
2. Click on the Scanning button on the left and select :
? Scan Within Archives
? Scan Active Processes
? Scan Registry
? Deep Scan Registry
? Scan my IE favorites for banned URL?s
? Scan my Hosts file
? Under Click here to select drives + folders, choose:
? All of your hard drives
Click on the Advanced button on the left and select:
? Include additional process information
? Include additional file information
? Include environment information
Click the Tweak button and select:
? Under the Scanning Engine:
o Unload recognized processes & modules during scan
o Include additional Ad-aware settings in logfile
? Under the Cleaning Engine:
o Let Windows remove files in use at next reboot
Click on Proceed to save the settings.

Click Start and on the next screen choose:
? Use Custom Scanning Options
Click Next and Ad-aware will scan your hard drive(s) with the options you have selected.

When finished, mark everything for removal and get rid of it. (Right-click the window and choose Select All from the drop down menu and click Next).

Reboot your computer.

3) Then please go here <>
and run the online virus scan. Please select the Autoclean option when prompted.


4) Close any applications you have running currently. Go to Start->(Settings)->Control Panel->Folder Options->View and select Show hidden files and folders. Also make sure to uncheck Hide file extensions for known file types. Now download and install Hijack This <>.

Do NOT put HijackThis in the Temp folder. Create a folder called, HJT, on your C: drive and move HijackThis.exe to that folder (ex: C:\HJT\HijackThis.exe). Now run HJT and click on Scan. This should take a few seconds. Now click on Save Log and name it hijackthis1.log.

5) Next download Hijack This Analyzer <> .

Unzip the program to the same folder where you saved the hijackthis.log file. Now read the README.txt and run the program. Type in y if you agree. It will create result.txt. Open up that file and post the WHOLE log file in the Security forum. .

6) DO NOT remove/fix anything in there since more damage may be done if you removed it improperly. Most of those entries listed are not harmful.

Register at

Cut n paste the security forum url in your browser:

Title your post: first time forum user, system crashes randomly.

Following these instructions explicitly will reduce the time it takes for problems to be processed, to the benefit of all.

Submitted by: Nancy R.



The problem could be bad capacitors on the motherboard. This has been an increasingly common problem in systems over the past few years. You can go to , read the article and see if your machine shows any of the symptoms described. I have seen a number of name brand systems plagued by this problem.

Submitted by: Alex S.



try this site it could be as simple as a faulty memory module. download the program to test your memory. You may find that one of the modules is faulty. You could also remove the modules clean the brassy ends with a lint free cloth and brush or blow the sockets out with compressed air, re-insert modules on at a time and test. If the first one does not work try the other, if it works you then know that the memory module is faulty. The answer could be that simple, or both modules could be faulty.

Submitted by: Ralph M.



I have had a number people approach me with the same issue. 80% of the time I have found that it is caused by a faulty peripheral, keyboards in particular. Also, Mice, USB web cams, etc. The latest, only 2 days ago, I have purchased a USB hub/card reader/sound ports that fit into a 5.25 slot. Having installed drivers for the card reader, my PC started restarting everytime a USB port was used. This could be a long shot, but I think it would be advisable to see if unplugging certain peripherals will help.

Submitted by: Alex V.



I'm a desktop technician with an organization of 1200 users. We have a certain brand of pc's that this same problem happens to quite a bit. We have found that when a pc shuts down intermittently, it usually indicates a bad motherboard. We have had some worms in the past that have caused this problem (the Sasser worm) but I doubt that is what is causing your problem. With all of the problems you mention, such as slow power fans, cmos battery replacements, etc., it really sounds like the problem may lie with the motherboard.

Submitted by: Tom F.



As a computer repairman I have come across this problem several times. You were correct to change the battery. If it is the battery it could be the new battery is dead too (it does happen). The battery may be in wrong also check the contacts. If you are able to go into BIOS and start your system without problem. And since it goes off randomly it is your power supply. 250 watts is not enough to run a Pentium 4 with hards drives and cd drives not to mention video card and so on. Those things take allot of power. I would recommend no less than a 425 watt power supply unit. I can guarantee it is a problem with your power supply. new ones are inexpensive off of e-bay.

Submitted by: Anonymous



I would start with swapping out the present memory stick or sticks, with known good memory. Everything that is handled by the Operating System, Uses memory, and if you have a bad or flakey memory stick, it will play havoc with everything. (Random Acts of Greif) Are very common with Bad Memory.

Remember the Operating System resides in Memoy, it is loaded there from the Hard Drive on Start-Up, and accesses libraries from the memory as well as the Hard Drive. When things go wrong (system resetting itself), it is windows way of trying to fix itself, it tries so many times and then usually if it is not successful, it reports a fatial error, and basically crashes.

You might also have a flakey CMOS?. Since you swapped out the old CMOS Battery.

An over heating CPU could also cause a similar out come, but I always keep spare memory sticks around just in case. Make sure the CPU is running Cool, check the CPU cooling fan for proper operation.

The CPU is the heart of your computer and the memory are it's veins, make sure they are operating properly. If possible swap each one out with, known good parts, but only one at a time. (Trial and error)

I hope this helps some.

Submitted by: David A.



Two possibilities come to mind on this problem. The motherboard could be overheating. Or there could be a circuit on the motherboard, video card, memory chips, cpu, etc that looses connection at a certain temperature or certain vibration.

Have you tried running a temperature monitor such as Motherboard Monitor 5 to see if the restart is always at a certain temperature? Motherboard Monitor 5 has a logging feature that can be set in any increment size you want so that you could check after a restart to see what the temp was.

If there's not a temperature correlation on the motherboard to the restarts then it's not likely the temperature that's causing the reboot, but could still be triggering the reboot if there is a bad or cracked circuit on the motherboard, memory card, video card, etc. Could be any of them if that's the case.

I'm guessing it's not software related since it restarts randomly anywhere within 3 minutes or 3 hours. However, before you start replacing hardware parts, I would try reinstalling the OS just to be certain nothing was corrupted.

Submitted by: Jeff J.



Have seen this before. It is most likely corrupted ROM bios. You don?t need to replace the chip. You need to go to the dell website and download the latest ROM bios for your machine.

This is the URL for dell dimension 4500 flash bios. You will need to put it in a floppy that can boot dos. Then install the new flash Bios from the dos boot floppy, then reboot the machine. The key is that the basic input output system is incorrect if you are loosing clock time and the reason the system reboots for the same reason. After this recheck the hard drive for any errors using the tools section of windows explorer. (Right click in explorer on the boot drive go to properties, tools and check now. This should correct any hard drive errors from the chronic system crashes. Note you need to reboot the system to allow windows to check and repair the boot drive

Submitted by: Lawrence J.



Derek you said that the computer randomly reboots and has no discernable cause from 1 particular circumstance. the first thing I recommend trying is going into control panel double clicking on system go to the advance tab and click the settings button under the heading "Startup & Recovery, in the screen that appears in the section marked "System Failure" untick the check box called "Automatic Restart" then click on ok on every screen until your back in the control panel. once this has been done reboot and see if the problem occurs again. sometimes when this option is enabled you will find that if a minor thing like running low on memory occurs the computer will have to do a dump of physical memory which causes windows to crash the restart option hides this action from you by restarting your computer while the memory dump occurs in the background, therefore after disabling the restart option you might encounter random memory dumps, if that happens it might be an idea to purchase some more RAM for your computer. I would like to hear how it all works out for you.

Submitted by: Stuart B.



Dell Dimension 4500 is a fairly old PC system (2002's) taking as reference the actual progress of hardware models specifications and software evolution.

The only thing that appears to be the cause of this Problen is (as Derek B. says) the power supply.

The original 250W PSU (850 BTU heat disipation) power supply is too low for actual hardware peripherics, and new software requirements.

But if Derek wants to make good additional "feeling" of what is happening inside the PC, he can check some variants using diagnostic software like "Sandra Lite" (Shareware) that can be downloaded from here:

Another diagnostic software that can help is "MotherBoard Monitor" (Freeware) for testing heath in system board, and can be downloaded from here:

Submitted by: Antonio P.



Chances are that that's a driver problem. It could be a printer, scanner or other peripheral that causes the restarts. Do you get a message when the computer comes back on that says that the system has recovered form a serious error? However, fixing this problem may be more difficult that just disconnecting the devices one by one to see if the problem disappears, as the driver is not actually removed when the device is disconnected. Try that first, but the only way to be sure the problem is not software related (which it most probably is) is to reinstall Windows, and install each device one by one to see when the problem occurs. There may be driver updates on the manufacturers websites that address this problem also. Although rather scallered, I hope that helps.

Submitted by: Edward T.



i had this problem on my computer. after installing a new sound card. to put the front bay which came in i took had to take out the floppy connector to power it. the the computer started randomly rebooting.i thought it was because it was not happy about the floppy drive not having enough power, but i was wrong. After it restarted it would always say that it had recovered from a serious error and please could i send an error report. i never bothered as my dad always said that sending error reports did not help. but then i tried it and amazingly it came up with the solution. it said that it was my sound card drivers were not up do date. so it even gave me the link to the update site where i could get the updates. it runs fine now. check you are up to date on all the programs you have on your computer. even is you have not installed any new hardware your computer may have come like this from the manufacturer. so if you get and error message come up about a serious error make sure you send it. hope this helps.

Submitted by: Christopher B.



The first thing I would look at is to see what gets loaded at Windows start up by clicking ?Start?, ?Run?, then type in ?msconfig? (no quotes). Go to the ?Startup? tab and see if you can find anything there that perhaps doesn?t have to start up every time Windows Starts. You can experiment with this, by unchecking one item at a time and see if the problem corrects itself. You can always go back in and recheck items previously unchecked if you find that something doesn?t run that you need. You should also look in ?Start?, ?Programs?, ?Startup? and examine any entries there. Sudden restarts are often caused by memory chip problems. If you feel confident, open up your PC and see if there are more than one memory chips installed. If there are more than one, try removing one (with the computer OFF, of course) at a time and try to see if the problems stops. If problem is still there, reinstall the chip and remove another one. System clocks can be innaccurate due to the clock chip being defective, but this is a function built-in to the motherboard, so you might be forced to replace this component, but in the suggestions I gave above, you need to try to isolate a ?rogue? application before replacing the expensive stuff. I also am a believer in TIMELINE. Try to remember if you installed anything just prior to the reported problems. Perhaps restoring your computer to a time BEFORE the proble might fix the issue. Good luck.

Submitted by: Lorenzo Q.



I used to be a dell computer technician; I have seen this issue many times. What you need to do is go to their support website at Type in your service tag that is on the back of your system on a white tag labeled service tag. Then select system type dimension 4500. Then select troubleshoot. Do a search for random reboot. It will tell you all about the issues of none existing ide devices. You will need to reset your defaults and then save and reboot. This should take care of the issue if it does not then go back into system setup Press alt+ e simultaneously and this will reset your nvram. Reset your defaults again save and exit system setup and reboot. Your issue should be resolved. If you have installed any other peripherals other than what actually cam with the system you might have to reseat these, specially your ram, if you open up the case you might as well reseat all of the peripherals while your in their why have to do it several times. I hope this is help and have a nice day. Just a friendly reminder if you do have to go into the case make sure to ground yourself by touching the metal on the case before touching any of the components inside, this will save you a lot of heart ache and money.

Submitted by: Lee N.
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by Alan Parent / April 27, 2006 10:27 PM PDT

In my humble opinion, the most likely problem is the CPU to memory amd MoBo FSB mismatch. There was a problem with MoBo's that appeared to support a particular CPU but the clocking didn't support it. This could support the random rebooting.

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Right on, Alan
by talon1812 / April 28, 2006 11:32 AM PDT
In reply to: Motherboard


I have read your posts and you really seem to know your business!!! Many people get on these forums and spout random gibberish.
The problem you talked about with the motherboard/cpu/memory FSB is exactly the problem I had with my computer. I have an AMD Athlon XP 2.1 GHZ CPU, MSI motherboard. Somehow, I don't think that the speed of the memory is compatible with the CPU. When I had it set at the default setting, it would constantly re-boot, within a minute of loading windows. I had to change the jumper on my motheboard into a safety setting to get it to run. Now, my system says I have a 1.6 GHZ chip, although it runs stable.
This has always bugged me, as I feel that it is not running at it's peak speed. I built the computer myself, so no tech support. The only resolution is to let it go the way it is.
The motherboard is an MSI MB, with onboard sound, video, lan (GASP). I know some people hate them, but I like the all-in-one motherboards. It has an onboard Nvidia graphics card, and also the main chipset is an Nvidia. I have read that these Nvidia chipsets are very, very finicky about the memory that can be used.

Thanks for the insight.


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This happened to me, here's what solved my problem
by Lee Koo (ADMIN) CNET staff/forum admin / April 26, 2006 9:36 AM PDT

We have faced this problem several times recently with PCs that have a build up of dust in the cooling fins on the processor, the processor is overheating and shuts down to protect itself. However the default for Windows XP is to automatically restart when it stops unexpectedly. You say that the PSU fan is barely blowing, it could also be the air input to the PSU is getting blocked. From a few questions we have asked the PCs that are sat on the floor are picking up more of the dust and fluff than when raised from the floor. I suggest that you take the cover off the PC and look to see if dust is blocking the processor fins or the PSU input. A soft paint brush (real bristles to avoid static electricity) can gently dislodge the offending dust and fluff and a vacuum nozzle will remove the dust and fluff. For the harder to get at places try an Air Duster aerosol (one that specifies can be used on electronics). Don't forget to vacuum up as much as possible to avoid the system re-clogging itself.

To stop the PC restarting after an unexpected shut down From the Control Panel Click on System (its is in Performance and Maintenance if you are in category view), click the Advanced Tab. Click on Settings in the Startup and Recovery section. De-select Automatically Restart in the System Failure section.

We have a Springer Spaniel who moults in the spring, leading the PC to take in his fur to clog things just before it starts to get warm if we are lucky in our English summer. We now check PCs annually as the warm weather starts to minimise the risk of problems.

Hope that helps

Submitted by: Jonathan F.



My answer is that you should in fact change your PSU. I myself have a similar problem. Once my computer was on it decided every so often to randomly restart itself. I looked at a few internet sites and come to the conclusion that it was either my graphics card or my CPU that was overheating. However, I have a 400W PSU, so the problem isn't power, its the temperature of my system. What I did, and what I suggest you do, is to increase the temperature threshold at which your computer is set to. For this you will probably need some overclocking software or a PC health configuration. As well as doing this I installed an extractor fan to the back of my computer and it works really well. If you keep getting the same problem then I suggest buying a few more fans for your computer, and even possibly some cooling substance to apply to you CPU.

Hope that helps.

Submitted by: Andrew C.



I was having a similar problem with a brand new computer. I took it into the shop that built it and they ran it for 24 hours without it restarting. As soon as I brought it home, the restarting began again. This led me to think that it had to be something I had connected to the computer here at home. I disconnected all the peripherals I had and then started reconnecting them one by one. As soon as I connected my card reader, the problem started again. I bought a new card reader and it has never done it since.

Submitted by: Lesley B.



It happened to me as well; the problem turned out to be an overheating USB hub!!! Weird! the hub I had was made by Belkin and I replaced it with one from Staples and have not had the problem since. Also, I no longer keep my flash drive plugged into the hub as the hub gets very hot when it is plugged in.

Submitted by: Linda E.



It may be that the memory module is going bad. I had the same problem and thought it was the internal battery but it kept restarting at random. I also thought it was the power supply but I have a 450 watt unit. Then I thought that the motherboard was at fault in which I thought not because if it was then the computer wouldn?t start at all. I also considered the Hard Drive but then again I didn?t hear any unusual noise, did a thorough drive check and came out okay. I was almost going to reformat the HD!

The last thing that I didn?t test was the memory module. I had two 512mb sticks and tested each one individually. Lo and behold one of them had the same symptom. The memory stick nearest the CPU was the culprit. Replacing that with the other reported no symptom.

Since I was forced to buy a new memory module I went ahead and filled the third bank with another 512mb module. Now I have a total of 1.5 gb of memory. Performance really improved and no more intermittent restarts.

Submitted by: Tom



So, your computer "randomly restarts itself"? You could try to come up with various answers, but I'm inclined to cut right to the chase. Chances are Very, very good that each and everytime your computer restarts itself, it's doing a core dump. One of these days, chances are also very, very good that it will shutdown instead of restarting, and that will be it. Why? Your Motherboard is going.

I've experienced this before. Three times, to be exact. The good news, for me anyways, is that it was never my machine. I did, however, have to swap out the Motherboard for the people it did happen to.

My advise is to replace the Motherboard Before it goes completely and takes some other, possibly really expensive, computer part with it.

It's not hard, and could be a chance to upgrade your machine, or at the least, set it up for a future upgrade and continue to use the parts you have right now. Even if you don't think you can do it yourself, it's still a lot cheaper to replace the motherboard, than to replace the whole machine.

You might say, "What the heck, the machine didn't cost me anything anyways." That just makes it more insightful to replace the motherboard now.

Submitted by: Putergoddess



I was having the exact same problem with my Dell Dimension 8200 which is also a P4 2.1 GH machine. I found that at times certain mouse or KB inputs would cause the restart. After days and weeks of loading deleting or reloading drivers the symptom didn't get better. I would usually be on the computer when it was late and quiet in the house. I did notice that at times the power supply fan would change pitch when I would do a mouse click and then it would sometimes restart. The power supply ultimately failed after the warrantee period and I replaced it with a generic unit that was rated 100 watts higher. The fan speed is now constant and the restart condition has not recurred in more than 2 years. I would bet that it is the power supply.

Submitted by: Art S.



You are correct in thinking the power supply is at fault. I had an E-Machine that after a few months from when I bought it restarted hours after I turned off the tower. I'd turn it off at night and when I'd wake up in the morning it had restarted by itself sometime during the night. This continued for a few months each time restarting sooner until as soon as I'd turn off the tower it would immediately restart. When I finally called tech support they told me the power supply was bad and sent me a new one. This should also take care of the problem of your system clock, after all if the power supply is bad it can't keep the time much less any programs running at its max.

Submitted by: Barbara G. of Metairie, LA



I have had a similar problem on two different PC?s in the last few years. I call the problem ?Spontaneous Reboot? because the PC will randomly, and without warning, reboot itself. I originally thought the problem was a hard drive problem since the reboots always seemed to happen during times of high disk activity. I reformatted my hard disk several times and then reinstalled Windows, etc. Same problem!! Very frustrating and angering. Then one day a light came on and I thought the problem might be memory related. So I removed the memory cards one at a time (my system only had 2) and discovered that once I removed a particular memory card, the problem never reoccurred. The vendor replaced the memory at no-charge (kudos to Kingston) and the problem has never ever reoccurred. So clearly it was a bad stick of memory. Two PC?s, same symptoms, same fix.

Submitted by: Chip L. of Dallas, TX



I had the same problem and tried everything such as virus checking like you. My computer would constantly shut down and restart. The power supply can cause this but there is another culprit you should check. MEMORY! I have the same computer that you have as well. I thought my power supply was the problem. After checking all that I could without actually replacing anything yet....I called Dell support. The following fixed the problem. When you purchased your Dell you should have received a Dell Diagnostic CD. Support told me to insert this CD and reboot my PC with the Dell Diagnostic CD. It will run a series of test on all your hardware inside the Dell. It found one stick of my memory was bad which will cause your PC to reboot. I took out that one stick and what do you know... It stopped rebooting ! Bad Memory was the problem all along. If you don't have a Dell Diagnostic CD then I suggest (that is if you have several memory sticks in your PC) alternate taking each one out and give that a shot.

Submitted by: Peggy



I had this annoying and so frustrating problem, and it went on for weeks. Clock would get screwed up too. Long story short, turns out my hard drive was failing. PC's boot so fast these days I wasn't noticing the hard drive errors on booting up (a WD drive using the WD monitoring software) and messages telling me to back up my drive as it was failing. I noticed the error messages, finally and by accident one day before the drive really failed and the PC would not boot at all -- drive could not be found, no matter how many times I tried it. I think it turned out that the master cylinder index was corrupted. Replaced it and never had the problem again. Simple, huh? Don't know if it's the problem Derek has, but it was mine, apparently.

Submitted by: Ken



I had "Random Restarts" twice, on two different computers.

Once, it was a bad chip. That was a few years ago. The computer was new. It took hours of testing to finally get that chip to fail while the seller was running the tests. Solution: A new RAM chip.

The other time, it was the hard drive connection that was loose. That computer had been running over a year. The fan vibrations caused the hard drive connection to "unplug temporarily", just enough to force a windows reset. Solution: Push the plug back in.

Submitted by: Andre P.



I have dealt with this before and, for my situation, it turned out to be power sags. To diagnose, check your power settings in the control panel and set your PC to NOT reboot after power loss. Then if you get a sag that is big enough to drop your PC, it will stay down until you reboot it yourself. To fix my problems, I notified my power company and they did some work. I also put my PC on a UPS, one that has software that monitors incoming line quality and evens out both spikes and sags. If your power supply is at fault - and it seems a little small to me - the UPS power monitoring software will show good incoming power and you will still have drops. A good UPS is a good thing anyway, so that's what I would do.

Submitted by: Linda



Well I had the same problem exactly 1 week ago. My computer kept restarting randomly. I changed out the power supply and I have not had a single problem yet. If you replace the power supply then you should be fine . I also recommend that you buy the power supply new. Then you could take it back if it was not the problem. You will not be out of luck that way if you buy new and take it back for refund. I would bet that the power supply is your problem. Good luck and happy computing.

Submitted by: Joe K.



I had the same problem with an old HP computer. I did every thing you could think of to find the problem. It shut down and also did restarts any old time it felt like it. After eliminating everything possible the only thing left was the power switch. I sprayed it with some Tuner Control cleaning lubricant from Radio Shack and presto it was cured.

Submitted by: George G.



I was having the same problem on an asus A7V600-X motherboard. I would be working along and all of a sudden it would just drop out and start rebooting. I went thru countless items trying to solve the problem. At first I thought it was a problem with the power supply. No luck. Then I thought it was the hard drive so I sent it back to WD. The old one was only 4 months old. Not long after sending it out I discovered it wasn't the hard drive at all. Then I did a bios upgrade and that didn't fix the problem. Then I tried changing hard drive cables, still the same problem. Then I called asus and they recommended I send the cmos chip to them and have them check it out. It came back Ok with the latest upgrade. Still no luck. I then called asus back and they decided it was the controller on the motherboard. Before sending it back I decided to try the hard drive cable again with no luck. I sent the motherboard to them and they sent a replacement board. Still the same thing. I was just about to give up and buy another motherboard. I decided to talk to asus one more time. I was able to talk to someone that knew all about that particular board on this phone conversation and he told me that nothing *_we_* (meaning asus) had tried would cause or fix the problem I was having. After some more thought I decided to try one more hard drive cable (#3) and that fixed it. As far as your clock not keeping time, I'm not sure about that. I don't remember if my clock was losing time or not. I was more concerned about the rebooting problem. So before you spend lots of money like I did sending items back to the manufacturer, check out that hard drive cable!

Submitted by: Randy P.



I had a similar problem...after getting a new power supply, it still happened and we finally decided that it was overheating by being placed in the CPU cabinet of my new computer desk that has a door to keep it shut.

Once I moved it out of there, and now use that cabinet for storage of sundry desk items, the problem went away...It must need more air to circulate around the unit , and the closed door prevented make access to the CPU, I purchased a rolling stand to make it easier to access the back of the unit to plug in all of the cables, printers, microphones, speakers, palm pilot, etc.

Not sure if it has any relation to this item, but I also purchased a Logitech wireless keyboard and mouse and my computer works like a charm now...hope this helps...because I have been there and know how frustratin it was

FYI, my computer is about 4 years old, and after a recent move, I doubled the memory, tuned it up, cleaned it up...then had to get the new power supply, treated myself to the new keyboard and mouse (the pins on the old keyboard connection were bent) I am now happily good to go.

Submitted by: Brigid D.



I had a similar problem with an Albatron MOBO, ( KM400 PRO ). I was using 2 x 256meg Modules of RAM, ( SDRAM PC3200 (DDR400) ) with On Board Graphics. I narrowed it down to a problem with using 2 ( or more ) RAM modules, with On Board VGA. If I used 1 module, in any DIMM slot, it was fine. 2 or more and shutdown time.

My solution was to put a AGP VGA board in and disable onboard VGA. ( I had a spare board, so it was the easiest solution). A single 512 RAM module may have solved it also???? We have been happily surfing ever after. Hope this helps or gives you something to check...

Submitted by: Paul M. of Queensland, Australia



I've seen this problem a few different times Derek. I have a Dell 4600 Pc, which is very similar to your 4500. I also know several other people with Dell's of the same type, and this is an issue across the board. I found that the socket on the power supply is loose fitting, so the power cable can come out. Those PC's that are up against a wall can be bumped, so the power cord jiggles in the socket, causing momentary power loss, but not long enough to just turn off the computer. The gap is so short that the computer appears to be restarting, but only once the cable has settled. Buying a new power supply will help, and i especially recommend this for your situation because the fan appears to be slowing. By far the easiest way to fix it is to just move your computer several inches away from any object that could hit the power cord. Good luck!

Submitted by: Andrew P.



A family member of mine also had a similar problem and reloaded all the software, checked out the power supply and disk drive. Finally, we scrapped the computer and tried the parts in other computers and found that the Processor had overheated and basically died. After reading on the web about other computer having similar problems it seems that the cpu blower setup doesn't do a great job of cooling the computer if it is on all the time and left in a non-temperature controlled environment like a non-airconditioned room.

Submitted by: Dane C.



Derek, I also had experienced the very same problem with my system just a little while ago. The only difference is that I lived with it for about a year. I had experimented with different things, swapping out different pieces with new ones for the course of the year. I had tried different memory, different hard drives, different power cords. At one point in time I had even changed out a power supply as it had failed. I had thought that it would simply be the power supply failing, but was disappointed to realize it was not. I, also, had the issue with the system clock losing time. After speaking with many knowledgeable people, I simply couldn't figure out what it was. Finally, about the beginning of this year, something went on my computer and it just wouldn't turn back on. I found this to be the motherboard, and replaced it. Since this replacement, I have not had a single problem with restarts or losing time on the clock (all of this with the same components, even the same processor, in a different motherboard). Certainly, try the PSU first, and then the RAM or even processor after. If all else fails, most likely the motherboard is the culprit. I hope this helps you out, random restarts are quite frustrating, I know!!!


PS - This was all on a Home Built - Athlon 2600 XP - MSI MicroATX Motherboard - 512mb Crucial DDR - 450w PSU. Good Luck!!

Submitted by: Dan W.
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Unexpected system reboot
by NawelR / April 27, 2006 7:57 PM PDT

From times to times my PC used to restart without any obvious reason.
I noticed that this I experienced this issue mainly in summer and when the temperature was higher than

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I know this issue.
by warlock_ba / April 27, 2006 9:29 PM PDT

But i didn't see it ever mentioned above.
I'll write my quickstart guide for this issue, it might help ...

1. Check that the PC Case is correctly ventilated (more exactly, check system temprature (not CPU temperature) and check that the IDE/or other data transferring cables are not near the Processor, or close by it), since they heat up, reset the PC, which then cools down enough to run for a while, but then another reset will come for sure.
2. Check that RAM chips are correctly in place, and that no dust has entered between the RAM contacts (eventually clean the RAM slot).
Same for AGP cards.
3. REMOVE SYSTEM BATTERY for 3-5 minutes (eventually while battery removed, do a Short Circuit between the two pins of the battery slot, this fastens up the discharge process)! This is the major thing that fixes this issue. Windows XP in combo with the NVRam of the Motherboard do very weird stuff. That can even lead to not beeing able to start the PC until removing the battery and waiting for a while.
4. Check that the plug where you plug in the PC has GROUNDING connected right (not -, not +, but GROUNDING, at least for european plugs). Do not use for grounding improvisations. <= THIS FOR ATX IS MANDATORY
5. Check that in the PC plug you don't have also connected a wash mashine or other high load equipment.

Then we go to more PC oriented issues:
6. Try getting a good monitor, or bad one, which shuts down slowly or just enable minidump to disc of the system blue screen/system crash (you might have a blue screen, that goes over to fast, so that you see just a plain reset, but in fact it's MS Windows XP dying). If you are sure it's no blue screen change the Power Supply, then RAM, then Motherboard, and in the end CPU.

7. If you have a blue screen, first suggestion is to check which file caused it (see a minidump file log). Usually a sys or dll generates it. It usually belongs to a driver from your system. Update / remove it. That might help (other cause can be the component itself that is driven by the driver; but usually it's just a bad driver from the manufacturer).
EVEN CODECS, which most of them are driver like built (since they do directly integrate with direct X) can cause this behaviour.
Example: Real Player resets Windows XP 64 ALLWAYS!
The last software reason, indeed can be malware. But i didn't encounter any, that really does this.

Usually it's issues 1-5 that solve 98% of this issues, 1.5% is the driver/codec issue (7), and (6) is last thing you should do, since it's another 0.5% (but if you bought the whole system in one piece, this should never be the case for you; heapens only in poor countries - like mine Grin - where you assemble your own PC from God knows what parts, from what friend :D).

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Check Power Supply
by procseed / April 27, 2006 9:34 PM PDT

I've had that problem in the past and it was the power supply. A program called Motherboard Monitor can be downloaded for free and you can actually watch the power supply voltage drop right before your PC does it's restart.

Hope that helps.

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Software conflict
by b430 / April 27, 2006 10:37 PM PDT

My Dell 4100 with ME had a similar problem, and all mechanical tests proved OK, including replacing the cmos battery. Slow clock, rendom reboots, and all of that frustration. Dell's service people agreed that I had a bad motherboard, and sent out a tech to replace it. They do have a very good support operation, and you can understand almost all of their people. You just have to remember that they have a protocol to go through before finding the problem, even if you know what it is.

They replaced the motherboard, and the same thing. Disabling boot-up software 1 at a time dentified my networking software as the source of the slow clock and the reboots. XP includes it's own network software, so you shouldn't have any third party network software installed for your intranet, but it doesn't install the netbiu protocol by default. I believe that it is on the CD under tools, and that may help resolve the issue if you are networked. Also ensure that you have one or more IPX/SPX protocols installed.

I'm sorry, Dell, I didn't mean to cost you a new motherboard back then.

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Computer Rebooting
by georgina23 / April 28, 2006 12:00 AM PDT

Don't know where to start, mine has re booted on its own about 5 times with in three days and its never rebooted on its own before. It's about 4 years old and homemade. It is not a Dell and it did have some dust so I cleaned it out real good checked all of the connection and cards to make sure that they were seated and started it back up. Its been running about an hour and all is ok for now. I realy thought it might be a virus when I saw that so many people were having the same problem at the same time and I still suspect that, if it runs all day for 3 days without rebooting I will though that idea out. I don't think that its the Dell thing because too many people are having the same problem. and going in and shutting down the auto reboot is not the answer because if its dust or another system problem you could cause harm to the computer. I guess that software conflict could be the problem and I receive updates everyday with Spyware Dr. and AVG Anti-Virus. By the way I am running Windows XP.


Jim Mullens

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This happened to me, here's what solved my problem
by jpromeo / April 28, 2006 12:03 AM PDT

I recently had the same problem with my HP Media Center PC. It took a strange path to develop the problem but let?s just say it all started when I updated a driver for my ATI 9800pro video card required before I could begin playing Elder Scrolls. I started having MS Windows problems that eventually led me to roll back the driver to make the system stable again.
I then decided that I would not be denied Oblivion so I began researching hardware upgrades. I discovered my PSU was a bit too puny to power the latest video cards so I bought a 500 watt unit and an ATI X1300. While I was at it I also found memory on sale and installed it also. At first the increased performance was stunning and I was very pleased.
Within a few days however, I was experiencing random shutdowns and restarts. I did a hardware diagnostic and all appeared normal at first so I suspected it was still a Windows problem but it eventually led to cycling uncontrollably. That?s when I did a full OS recovery and what a mess I caused!
The system would not recover and kept giving me corrupted data errors. I sent away to HP for the recovery CD?s (well worth the $22.00 anyway). After getting some good advice and receiving my CD?s (several days earlier than expected) I began the recovery process. Immediately upon attempting to re-install the OS I started getting corrupted data messages and hardware error codes. At this point I thought I had fried something up to and including the motherboard and I almost hit panic mode. I settled down and started to progress through the problem logically. I removed all non-essential hardware ie. TV card, modem (never been used anyway) sound card and the new memory. I completely cleaned the inside of the machine at this point. There was no sense in having a gutted machine and leaving the built up dust behind. I left the new video card in with the OEM memory as the first big test. Voila, recovery was complete on the first try.
I re-installed the new memory and the errors reappeared. I removed the OEM memory thinking there may be some conflict between old and new but the boot issues returned. Afterward I knew I had a 50/50 chance of finding a bad memory module so I pulled one and luckily restarted with success. I then re-installed the OEM twin 256 meg modules along with the one good 512 meg stick which turned out to be ok also, leaving me with the culprit in hand.
I lost some digital photos, a few recorded television shows and some easily replaceable work data but nothing too serious since I do regular backups. What a journey but it left me with a sense of complete satisfaction afterward knowing that I eventually solved the problem without paying someone and learned not to panic or despair. I also began reusing my backup PC to serve as my home office and work related machine leaving the Media Center to be just that.

As a side lesson, when doing hardware upgrades, keep your receipts handy. I can?t find mine so now I am stuck with a bad 512 meg stick of memory until I can find that little piece of paper.

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This Happened to me as well!
by NAVY_ETC / April 28, 2006 12:24 AM PDT

Built the PC myself, tried everything suggested in other threads. Changed Memory, reformat, etc..) The case I used came with it's own generic PSU rated at 450W. when I swapped the PSU with a brand name rated at 400W, the problem stopped.

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auto restarts without a source
by iscnitzan / April 28, 2006 2:18 AM PDT

I had an annoying restart issue and suspected many components like the power supply, memory failure, intermitent internal electrical cabling, overheating
of the CPU, etc. However, I found the culprit by accident: when I moved the computer, it turned off.
I found the PS female connector had some corrosion, and used a contact cleaner.
Been working great even since.

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This happened to me too -- rebooting randomly
by quietthyme60 / April 28, 2006 5:29 AM PDT

I thought it might just be a Gateway "thing". I had one that started doing it very infrequently. As time went on, it became more frequent. Took it into Gateway store (still under warranty) and they replaced power supply. Because they had to keep that pc for a week (can you believe that long ?? Had I known it was just the power supply, I would have done it myself!!) I bought another Gateway as I needed it for work. Sure enough, near the end of the warranty on that Gateway, it started to do the same thing.Most of my peripherals were different, had changed from cable to DSL, so there werent too many common strings between the two, other than both were Gateways. I didnt even bother with anymore Gateways. I just built my own computer and gave up !!! But I sure was surprised to see so many responses !! Well, if it has to do with heat, my new pc has a guage on the front and two fans inside !!

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Random Reboot
by belair57 / April 28, 2006 11:05 AM PDT

I had this problem with both of my Emachines. Each time the reboots were progressively shorter in time span until the hard drive failed. Emachines put in five hard drives in one year, all Western Digital, all junk. After warranty was up I bought a Maxtor for both and have never had it again. Since then I bought two Western Digital drives as slave drives and they are in the trash also. I have had these machines running on Maxtor for almost three years now without a problem. If you have a Western Digital drive I would suspect it before anything else.

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Head off the problem
by Richard Schales / April 28, 2006 11:39 AM PDT

I find that the reason for the phisical meltdowns on PC's is the instabilities.
a. turning the PC off when not used and on to use it is hard on the components, because of inconsistant temperature and moisture issues.
b. cooling is vitle to these components for example.
I keep my CPU's temperature under 100 degrees F at all times.The motherboard and drives also under 100.
c. Although high heat can and will damage a PC.
so also cold starts and moisture when not running for a length of time.

It is best to let the machine run. I have 5 PC's that have been running for many years large cabinets and 2 cooling fans on the power, supper cooling for the CPU, and 2in front of the tower, and 2 in back.
This will head off problems from heat as well as moisture, which was probably the main culprit and now you are experiancing the results.

Richard G

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It might be a bad video card
by philco2 / April 29, 2006 4:46 AM PDT

I was having the same random reboot problems that you are describing. Mine turned out to be a dieing video card. Once I replaced my video card, and upgraded at the same time, I haven't had that problem since!!

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random re-start of computer
by kikus29 / April 30, 2006 5:03 PM PDT

this problem was there with me when I got a new computer assembled. I went for 915 original mother board and the CPU. i was in litteral tears when working on some important work, the system will restart automatically. all the work is lost. I started doing R&D. I disconnected all the peripherals and th additional cards. Started oner by one. But nothing hapopened. i changed my mother board, i changed my CPU, I changed my hard disk and what not, but could not detect the problem. So one day I decided to upgrade my RAM. It was observed then that the RAM was playing the havock. So if you have any problem like this then look for the RAM first. The RAMs available in market are spurious and they creat havoc.

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I had same problem and I solved it
by eamorales / April 27, 2006 6:55 PM PDT

I have a Gateway Desktop I forget what model but its 3 years old..Mine was restarting randomly also.I tried everything that was listed reformated and took computer apart cleaned it completely..but my problem was a faulty wire on my power button(the wire that goes from power button to mother board).What I did was turn the computer on and unplug the power button from the mother board and now it stays on with out rebooting.

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Easy Steps To Help, my computer randomly restarts
by YungJoc87 / April 27, 2006 6:55 PM PDT

Couple of easy issues I have dealt with in the past.
Do a search for file and folders on your drive type in *.net or dotnet.
Sounds like you have an old virus that many spywares and ante viruses fail to pick up. If you have the old virus this would explain the rebot and the clock change as well as other weird system activity. Also check symantec to see how to wipe out the virus complety.
If you have it, you might consider just putting a new hard drive.
Also check all softwares that you have set to auto updates, then tend to run in the back ground and some files require a rebot.
Be worth your while to through in a new battery as they are low cost. Hope this helps.

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Computer restarts
by smithjp3 / April 27, 2006 7:05 PM PDT

Derek, it is a problem with the heatsink retension assembly as the computer restarting randomly indicates a cooling problem and since you have already indicated no viruses on your system. Change the cpu fan and heatsink assembly and your problem will be resolved.

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Memory and dust
by TonyGore / April 27, 2006 7:24 PM PDT

I have found that memory and dust are prime suspects for this sort of problem (after power supply).

Dust - collects on the memory chips reducing the airflow and so these get hotter.

Sometimes taking the memory out and plugging it back in "wipes" the contacts giving a better connection.

Sometimes replacing the memory might be necessary. One cause is if the timing on the memory is marginal (overclockers beware), then it works for a good while before starting to become erratic. The cause is that with marginal timing, one thing is switching off at the same time that anither is switching on (put simply). This causes very large currents to flow. Where the tiny wires (bond wires) inside the memory chip packaging join the chip, these extra currents cause "metal migration" i.e. some of the metal moves from the wire to the chip. This causes the wire to become thinner, which increases the inductance and makes the signal pass down it more slowly, which in turn makes the problem worse.

As someone suggested, a memory test program is worth doing. I found a problem with error correcting memory that was only a few months old (not overclocked, I hasten to add), so it can happen on even new equipment.

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Try this
by r_rayjr / April 27, 2006 7:50 PM PDT

Even though you said you did a scan with your Antivirus program it could still be a virus problem. Remember something Virus will do something to make you antivirus program not detect it or even turn it off, but some how so that it is still on. Or what ever it does.

Any way I would go to Norton?s security website and run their online scan. It will not remove any virus it may find. But once you find out what it is you can look it up in Norton?s Virus catalog area and there it will tell you how to remove it.

Also if you want you can also do this in Safe Mode. Make sure, when you go into Safe more you choose the option with the internet connections. I do not remember what it is called. But on my Dell, 8250 there are 3 or 4 options for what type of Safe Mode you want to run. And then I would go to the link below and run the online virus scan. This way if your computer problem is from a virus, then the virus should not load and run in this Safe Mode. And you should not have to worry about it randomly restarting during the scan. If it still restarts in Safe Mode then it might be one of the other problems that some of the others said, like the cooling fan or what ever.

And just incase you do not know how it go into Safe Mode, here is what is said to do at dell Website.

Starting the Microsoft

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SORRY, Bad Link
by r_rayjr / April 27, 2006 8:02 PM PDT
In reply to: Try this

I just tried the link I gave for And it did not work. But if the Norton Antivirus 2006 you have is like the 2005 I have then all you have to do to get to the online scan is click on the "Help & Support" button on the upper right hand corner of the Antivirus screen. Then click on "Symantec Security Check" this will open a window to the webpage and you will have two things you can pick, click on "Virus Detection".

This will get you to where the link I gave in the last post was suppose to have taken you. I do not know why it did not work.

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Reseating devices?
by megakilljoy / April 27, 2006 7:52 PM PDT

I haven't read all the posts, but have all of the internal components of the device been reseated? I know it's basic, but it's still worth mentioning.

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My computer randomly restarts
by rswinnen / April 27, 2006 8:11 PM PDT

Controleer je RAM memory, de SDDR latjes geven slecht contact.

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random restarts
by dldelanoy / April 27, 2006 8:20 PM PDT

i'm not really familiar with dell but you might like to check your bios settings i had a similar problem i'd switch off go away and find the little beast had restarted ''all by itself''
my bios had a setting ''WOL'' (wake on lan'' enabled and so whenever the phone rang up she fired up. the bios in your dell may support this or a similar operation designed to wake up / switch on your system in the event of an incoming call ( i think mine has 3 such nominated events0 but all are now ''disabled''

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