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Why is my CPU running at 100 percent, when only three windows are open?!


Windows XP: Why is my CPU running at 100 percent, when only three windows are open?!

I run Windows XP (Home Edition)on my system and frequently find that the number of processes running can be as high as 63, with the CPU usage rising to 100 percent and a commit charge of 943M/2313M. I should add that this happens with only two or three windows open but minimized.

This completely takes over my PC and virtually brings it to a non-useful condition. Can anyone please tell me what can be done to help me safely bring the amount of processes down as I don't believe that all 63 are needed? Many thanks and kind regards.

--Submitted by Patrick N. , London, United Kingdom

Here are some featured member answers to get you started, but
please read all the advice and suggestions that our
members have contributed to this question.

Troubleshooting a slow PC --Submitted by Droid

Why is my CPU running at 100 percent --Submitted by Fatboy71

Runaway processes... --Submitted by Wolfie2k5

Check your processes & scan for viruses --Submitted by si

Try an "empty" start --Submitted by TreknologyNet

CPU at 100% running answer --Submitted by seking0011

Thank you to all who contributed!

If you have some additional recommendations or advice for Patrick, please click on the reply link and submit it. Please be as detailed as possbile when providing a solution. Thanks!
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PS Are Really Easy To Change Out....

In reply to: use a 650 or 750 watt ps....btw,

The older power supplies are not the ones I run with. I am like you I would change it out and it is not that hard. Just follow your wiring and connections to replace the PS that one has now with a new one. Good Luck to our friend with this issue!!

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PS Are Really Easy To Change Out....

In reply to: PS Are Really Easy To Change Out....

Hi PHLW19642002
Thanks for your input, I hope you can clarify a few points for me.
I think anyonecam has a good point as I am sure that I don't have viruses etc, the trouble is I don't know what a PS is, I am assuming it is the power supply? But I don't know what it looks like or where on the motherboard it is situated.
Or indeed how to determine the size of the unit that is now in place?

As I put in my mail to anyonecam (expecting an answer, as it is his advice) for the less savvy of us can you tell me where I will find the PS in order to change it?
How is the power of the installed PS determined?
Is it easy to change?
And what is ...BTW?

PS, I just remembered after a power failure some months ago I had a unit replaced and I am sure it was the Power Supply Unit, the numbers are below if they make any sense to you
+3.3V 18A, +5V 20A, +12V1 13A, -12V2 0.3A, +5VSB 2A
And my processor is a Celleron 2.8

I was wondering if they were up to the job?
Regards Tyler

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In reply to: PS Are Really Easy To Change Out....

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Many thanks Randy, these abbreviations are a pain.

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Probably the easiest way to figure out what these goofy letters mean is to look in INTERNETSLANG.COM. Or as Dirty Harry would say, GAMMD (go ahead make my day)!

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If you're not sure what the power supply is, get a tech.

In reply to: use a 650 or 750 watt ps....btw,

The power supply in a standard PC case is it's own smaller box. You plug the IEC power cord into the back of it, and it usually has an output fan and may have a mains power switch.

Inside the PC case, the other side of the power supply will have a bunch of tangled wires going to a variety of plugs that connect to the motherboard (sometimes more than one), the hard drives and DVD drives. There may also be a few extra plugs hanging around for further accessories.

In a "standard" case, such a PS can be changed simply by removing four screws and replacing each plug one by one with the new PS which is then re-attached with the same four screws. Sounds simple doesn't it?

Unfortunately, if your machine is one of those highly customized compact units the Power Supply may be non-standard and therefore not as easily replaced--you can probably electrically connect a "standard" one, but it may not physically fit in the case. Proprietary brand PCs are notorious for these sorts of issues.

If you're not sure, consult a technician to at least find out how "standard" your PS is.

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Possible answer for windows 100 percent

In reply to: Why is Windows running at 100 percent

The first stop as others have suggested is opening Windows Process Explorer and / or Windows Task Manager (by pressing Control - Alt - Delete) and examining what they report as running applications. Assuming you've done that, eliminated the obvious, have installed adequate memory to preclude excessive HDD data swaps, and are certain you don't have a virus / nasty problem, consider the following.

Norton AntiVirus, and some other programs, often absolutely insist on checking in with the mother-ship before the program will let you open a web page or e-mail message. If your Internet connection is slow, you may find the machine is non responsive until the information is downloaded and / or the connection times out. Keep in mind that some anti-virus type programs check back with the mother ship several times per hour to make sure they have the very latest information.

Desk top search engines, such as Copernic and the built-in Microsoft desk-to search, can sometimes insist on recompiling the index even though the configuration calls for them to stay in the background when the machine is in use. To recover control over the machine, you must halt index updating. If you let the machine resume index updating when you take a break for lunch or dinner, it usually will be well behaved when you return.

If you seek to open a directory with lots of images (.jpg), the machine may stop if it has been commanded to display a cameo image of each. Under some circumstances, the machines will store those cameo images.. At other times, Windows Explorer will create them from scratch and delay any meaningful work. Let it store the icons if you have enough storage, and no one should be starving for storage given its current low cost.

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xp running at 100 percent

I had the exact same problem that plagued me for weeks. With no applications running, memory usage was up to 100 percent most of the time, and the machine was deathly slow. I installed a registry optimizer and it immediately resolved the problem and now the computer idles at less than 5 percent usage.

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Runaway processes...

Patrick -

The taskbar may not be the where the problem lies. You might want to take a look at your system tray icons in the bottom right corner. I don't know where you got your system, but if its an OEM branded box, odds are your system came with a bunch of generally useless stuff called crapware. These are generally trial versions of different programs, Antivirus apps that tend to only work for a limited time, and other stuff that really does NOT need to be running all the time.

Given I have no idea what you've got running there, you might want to look and see what you can terminate with impunity. Stuff like Quicktime's QTask utility. Utterly useless. The only thing an app like the that does is hog memory you can be better off using elsewhere.

Some Antivirus apps - like Norton and McAfee have been known to be memory and resource hogs. You might want to give a lighter AV product a spin - like Microsoft Security Essentials or Avast. Neither tend to overload a system with wasted clock cycles.

You also don't mention exactly WHAT is running. If you're using a memory or CPU intensive app like AutoCAD, you might just have to sit back and wait it out.

There is one surefire way to see what's hogging the system resources. Fire up Task manager (right-click on the task bar and select Start Task Manager). Click on the Process' tab and see exactly what's sucking up the CPU's attention. If you get a chance, take note of the name of the app(s) running there, and look them up on the web. If it's something that's SAFE to remove, by all means go ahead and get rid of it.

You might also want to run Malwarebytes AntiMalware and Spybot Search and Destroy to see if you've got any spyware/adware running on your system. By all means, get rid of everything it finds malicious.

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In reply to: Runaway processes...

Howmany svchost processes are there?
My puter does the same thing and I have 7 svchosts running!!

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In reply to: Runaway

Theoretically, I suppose there could be any number of SVCHOST processes running. SVCHOST is a system process to run services contained in a DDL (dynamically linked library). The easiest way to see what services are associated with any particular SVCHOST.EXE is to use PROCESS EXPLORER. As you move your cursor over the SVCHOST.EXE processes a window opens up and shows you what services are in the process. If, for example, a SVCHOST is using almost all of the CPU you can look in and see what is there. Malware programmers can use this SVCHOST technique to disguise their devious attempts to foul-up your computer.

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Invisible disk activity

In reply to: Runaway processes...

Wolfie2K5 wrote

"There is one surefire way to see what's hogging the system resources. Fire up Task manager (right-click on the task bar and select Start Task Manager). Click on the Process' tab and see exactly what's sucking up the CPU's attention. If you get a chance, take note of the name of the app(s) running there, and look them up on the web. If it's something that's SAFE to remove, by all means go ahead and get rid of it."

I have a different problem that may be should go in a different thread, but to me it seems to have something in common. When my machine starts up there can be a lot of disk activity for several minutes. When I try to track this down (as above) I can't find any processes that look unusual or that are taking up much time. CPU activity is low. After a while it stops. The usual process near the top of the activity list are taskmgr.exe and dwm.exe, also svchost.exe, both normally and during the busy disk activity. I do have a SATA Raid HDD (I think that's what its called) and I have wondered if it has its own processor that is doing clever things to optimize the drive contents when the machine starts up.

I had thought that may be it was my virus scanner, Sophos, but I don't seen Sophos processes running then, although at other times I do so they aren't invisible. (Can processes be hidden?)

Is there enough information here to suggest what is going on with the disk activity?

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In reply to: Invisible disk activity

Hello, Wolfie2K5,
You did not say what OS you are using but I can comment on VISTA. When I was installing SP2 I had a problem so I called MS to find out why. One of the things the technician told me was upon startup WINDOWS compares the current OS with a previous copy stored in the WINSXS directory. This might be what you are noticing. I am not sure you can see this with something like PROCESS EXPLORER because it is possible WINDOWS has not really started yet.

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Invisible disk activity


Thanks Randy

The activity I described is under Vista - the explanation you give makes sense, thank you very much. It does happen after Windows has really started, eg after logging on and the desktop being populated. When I started up just now the activity was showing up on the google monitor gadget with CPU usage at least 50% (that's high on this machine) and also showing a lot of disk activity. Now all is quiet, 5 minutes later.

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In reply to: Invisible disk activity

Hello, sea.bass. I found some info that helps explain what happens at VISTA startup. Based on your response that the desktop is populated it looks like the SERVICE CONTROL MANAGER has probably finished its duties. I copied the following paragraph from an article by Mark Russinovich called "Inside the Windows Vista Kernal: Part 2". This can be found at URL:

Mark is a Technical Fellow at Microsoft and this is part of what he has to say:

If you've ever logged onto a Windows system immediately after it starts, you've probably experienced delays before your desktop is fully configured and you can interact with the shell and any applications you launch. While you're logging on, the Service Control Manager is starting the many Windows services that are configured as automatic start services and therefore activate at boot time. Many services perform CPU and disk-intensive initializations that compete with your logon activities.

If you want to see the actual bootstrap sequence start a PROCESS EXPLORER and click on the word "process" up at the top of the screen on the left side. If WININT.EXE has a "+" next to it click on it and you will the startup services. Run your cursor down the entries and you will see there are quite a few things to do.

Next time you logon and while your CPU is usage is high (50%) start PROCESS EXPLORER and click on the CPU column at the top (this will sort by CPU usage) and hopefully it will show you what process is generating all that activity.

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CPU running at 100%

In reply to: Runaway processes...

Hello Wolfie
Very many thanks for such a detailed response to my problem.Have been reading all the responses and at this stage have eliminated 15 items from STARTUP which in conjunction with now using just one browser instead of two seems to have done the trick.Using Task Manager for identifying the surge has been so useful.
Once again many thanks to you.

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Windows XP Using all CPU

This can be a common problem with XP as I too have another laptop I use with XP on it.
My thought would be firstly to ask if you have a printer connected?
How many icons on the bottom tray to the right are open?
All these will be processes that have loaded when you start up your computer. I would right click on the icons on the bottom right, if you have a printer, bluetooth device
Another thing would be do you have a General Background on your Screen or a Fancy Screen Saver? Even Quicktime. These dont need to be running at start-up, all that will happen if you are to exit out of these will be it will take a little longer for them to load when you need them to load.

I have this as a quick tip for making my XP go faster
I would turn off Windows Themes. Just use a Classic Theme.
right click on Desktop > click Properties > click 'Appearance' >
choose 'Windows Classic Style'.

Then I would go to Control Panel > System > Advanced tab /
under Performance click on Settings / Visual Effects tab >
Adjust for best performance / Ok / Apply / Ok
These may or maynot help you, but no harm in trying them out. Hope I am correct as I am just a self taught computer person but do read a lot and take a lot in

Goodluck Happy

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Check your processes & scan for viruses

I would do a few things to help alleviate the problem:

1. Back up your data.

2. Always check for viruses first. I would run a Malwarebytes' AntiMalware full scan (after updating the virus definitions, if you're using the free version). CNet's has this.

3. Reduce your startup programs to only what's needed. You can do this by running MSCONFIG from the RUN box, or use Ccleaner to view and modify your startup programs (much easier). Only allow those programs which you absolutely need to load at startup. If you have any P2P file sharing programs (Limewire, Bittorrent, Napster, etc.), get rid of them, or at least stop them from loading at startup. CNet's has Ccleaner also.

4. Install Microsoft's Process Explorer. Use this program to evaluate the processes running on your system. It's much more detailed than Task Manager. Search the web for those you don't recognize to identify them. (also available from CNet's

5. Uninstall IE toolbars - having more than one toolbar in IE will cause them to conflict.

6. Run Ccleaner, using it's default selections, to clean up your temporary files and registry. Set up IE's preferences to dump your temp files every time you close it.

7. Verify that you have completely deleted all remnants of any previously used anti-virus/internet security programs. Remnants can conflict with current installations. Using specific "removal tools" for the various programs usually yields the best results, then I would also run Ccleaner.

8. Defrag your hard drive using a good defrag tool such as Auslogics Disk Defrag (CNet's has this too).

9.. Make sure your virtual memory is set to "system managed" and your computer is optimized for programs: Start, right-click My Computer, Properties, Advanced tab, Performance Settings, Visual Effects; select "Adjust for best Performance"; under the Advanced Tab, select Processor Scheduling - Adjust for best performance of "Programs"; under Virtual Memory, click Change, and select "System managed size" for the paging file.

10. Evaluate your computer's security program. Many of them are system hogs. Having multiple auto programs could cause conflict and bog down your computer.

Good Luck!

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Thank you!

In reply to: Check your processes & scan for viruses

Good Day. The information you provided was accurate and correct. I used your instructions and I'm happy to report that the pc is working faster. Thanks again for the information and have a great day!

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CPU running at 100%

In reply to: Check your processes & scan for viruses

Hello Si
Yes, have eliminated 15 items from STARTUP which has reusulted in the disappearance of the surge. Was unable to download Process Explorer for reasons I don't understand but will try again.
Many thanks for you help.

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In reply to: CPU running at 100%

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Are you running Zone-Alarm as a Fire-wall...?

In reply to: Check your processes & scan for viruses

If so, be sure to turn "off" the debugging mode. CTRL and Shift and then Right-Click and the Icon in your system tray. Select the DeBug option and select "off" mode. Be sure to delete the tvdebug.log from your computer and then re-start. That, should help a lot. It also prevents a known 'bug' from letting the .log file from using up your entire hard-drive.

Also, note that past versions of AVG, will also use All your computers resources, switch to Avast. Uninstall AVG, of course.

Hope this helps..?


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Mine did the same thing

Two things have made my computer do the same thing in the past. It would do that when one of my Internet Explorer windows was hanging up or running funny and it would take up all of the resources. I shut all of them down and started over and it would be fine. Another thing that made mine do the same thing was when I had spyware or a virus running, but most of the time, it was the first issue.

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Also have 100% CPU problem

I, too, have a 100% CPU problem but I seem to have narrowed it down to Flash. I also have problems if I've opened up Adobe Photoshop Elements or LightRoom. I've learned to leave flash off in IE8 unless I have to go to a flash website and reboot before running any Adobe product.

What's annoying is that my computer at work is also a Dell, processor only slightly faster and has less RAM, but does not have the flash problem

-- Glenn

Dell Dimension 8300, Pentium IV 3.0 GHz w/ HT, 2.5 G RAM, Win XP SP3

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Is it possible that Java-based scripts are the cause?
I know my PC runs at maximum on certain sites.

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cpu on 100

This problem occured to me some years ago. From what I finally figured out, that was a virus extending the limit of the cpu to its top. Back then I couldn't delete it so I had to format the pc. I do hope that nowadays the kinds of the anti viruses can deal with it.

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Why is my CPU running slow -or- Intel Chips Out

I found my laptop at 100% CPU Usage and getting extremely slower at certain times, especially after it had been running all day (or, more). It was similar to what Patrick was saying, I didn't have many sessions open... maybe two or three.

Then I did a little investigating and found certain Intel chips have a built in feature to keep them from destroying themselves due to heat, they purposely slow down (to keep those little electrons from bouncing around too fast and thus creating more heat). Other chip manufacturers may also have this 'special' feature. Google only took me so far.

Solution: Prop up the laptop with two short wooden pieces of a 2x4 to allow air underneath. Boy did that look tacky, but it worked (sort of). Then another Internet search revealed 'Cooling Pads' for laptops. Thirty dollars later I was the envy of my home office.

Chip and computer makers just don't tell you about this 'heat problem'. But, evidently it's well know amongst the Gamers (with their need for the highest speed possible). They're known to add additional axillary fans, heat sinks, and such in the name of getting their avatar characters to move a little faster. Obviously I'm not a Gamer.

And, I have nothing good to say about those programs (like anti-virus scanners) that say they will run during your idle time but won't give up the ship until they're done. Pretentious pigs!

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When you go to process in task manager is there any iexplore process but you don't using IE.If there are many of them you have a sistem error and you must to reinstall sistem.I hope this helps.Cheers Fem@

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Windows xp problem (CPU)

This is very general problem to a computer. Check process which consume your cpu using task manager try to end process. Do a full scan to your computer. it may be cause by some virus or viruses or it may be cause due to new program install into your computer. remove those programs if it is necessary. If the problem not solve then format your computer and after that do a full scan to your computer.

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Why is my CPU running at 100 percent, when only three windo

if one of your applications is a zinga game like farm-ville or fish-ville then your computer is under powered, as they take up a lot of processing power.

you can investigate what is taking up so much cpu usage by opening up the windows task manager by the ctr-alt-Del keys. Click on the process tab, Then click CPU twice, This will reorder the processes with the highest numbers on top. if your browser (explorer.exe or Firefox.exe) has high usage, it is one of the windows you have open that is taking a lot of processing power(like farm-ville) in this case, you may be able to do a memory upgrade, clear you browsers cache, or make sure you have 25% free hard drive space. If you have done all that, you may need to only have 1 window open when playing this type of game.

If this is an application, write down the name with the high CPU usage and Google it. Windows Defender comes to mind which caused high CPU usage in my xp system at random times. After you tracked down the CPU incentive application, you can then decide to remove the application with windows START controll pannel ADD/REMOVE APPLICATION.

Hope this helps

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