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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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Me too!

My system develops this condition regularly over time. But then I tend to keep my machines running without a reboot for far too long.

So, here is one remedy: Reboot when it starts bugging you. The chances are relatively good that it takes a while before the CPU use builds up again - unless it is something systematic, such as an indexing service or virus scanner. Those would probably resume straight after the reboot and there is only one way to stop them, and that is to configure them away.

The starting point for a diagnosis is the task manager - as described by several contributers already. Go to the "Processes" tab, click on the CPU column header - all tasks are now listed in CPU use sequence, increasing, the culprits at the bottom. Click again and the list is sorted in decreasing order - now the culprits are at the top.

The "System Idle Process" is harmless, that's what Windows does when there is nothing else to do.

If you see a browser at or near the top it is more likely the web sites you are currently viewing rather than the browser itself. I just wish there were a way to see which page is causing the problem.

Virus scanners tend to be overwhelmed by the challenge of a well-filled terabyte disk and will sit there gobbling up lots of CPU, possibly for days and days.

My problem usually comes from something called "svchost" - and there are several of them running, but only one has the excessive CPU use. This is where phase two of the diagnosis is required - "Process Explorer" from the sysinternals team, now owned by Microsoft, but by the looks of it just as useful as they were when they were still on their own. Process Explorer can be googled and downloaded for free.

Process Explorer can give you the startup parameters of the offending process - and with "svchost" or "rundll" (another one of the "usual suspects") that is where the actual information is. That is if you can read it - mine says " -k netsvcs" and I only have a vague idea what that refers to. So that is where my advice ends, unfortunately.

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Troubleshooting a slow PC

This issue is common but there are many possible causes. Here are the things I would do to investigate the problem:
1. Check your ram size, and upgrade if it's less than 1 GByte. These days anti-virus software is now so huge that the ram is completely filled up when a scan is taking place. This causes the paging file to go into overdrive & hence the 100% usage.
2. Run a malware scan. I recommend Malware Bytes' Anti-Malware, you can get it from cnet.
3. Turn off programs that run at startup, which you don't need.
For this you can use either msconfig, which you will already have (just hit alt-r and type that in), or microsoft's Autoruns which I prefer. (
When you try out Autoruns, stick with the Logon tab and make sure you know what you're turning off (use a google search on items that you don't recognise, but be careful what you believe in the search results - some sites love to describe everything as malware).
4. While you're at the sysinternals site you should also fetch process explorer(, because it should be able to show you which programs are taking up all your cpu, with much better accuracy than the task manager.
5. If you're reached this step and still can't find the cause, then consider that if it's going to take you more than two or three nights of work to find & fix the issue, your time might be better spent with backup & full re-install of Windows - always assuming that you have all the relevant OS, driver and software install discs of course.

Happy hunting

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Slow cpu

In reply to: Troubleshooting a slow PC

I clicked on both links in your writeup and they go nowhere.

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Bad links - not

In reply to: Slow cpu

Doyle, the links embedded in the post accidentally included the trailing right paren. Don't click the link. Copy/paste it in to your browser and then remove the trailing paren.

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Slow computer:The links in Droid-07/05/10 23:05 to Patrick

In reply to: Bad links - not

Even after deleting the brackets, neither link got me anywhere. But I've learnt something useful about the general approach, and probably haven't got enough "Available Memory" (387480 k), though I'm not playing any "Games", or "Flashing". Just found three instances of Search help operating, and removed two from the Startup.

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I use this program. In the tools tab...there is a simple interface to 'dis-able' programs that want to run at start-up. It also is an excellent way to clean temp files and reg clean. Good luck.

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In reply to: ccleaner

Yes, I use CCleaner regularly too. It can find & remove all sorts of useless junk, saving space & speeding things up. I use the Cleaner and Registry features with all the options left at the default.
I can also recommend Defraggler, from the same company, which allows you to defrag only the files, or a selection of files, rather than the entire disk. Much quicker than a full defrag.
Both titles are free, though donations are encouraged.

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links not working

In reply to: Slow cpu

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

In reply to: Troubleshooting a slow PC

the issue is very common and the only answer is of Memory, One should upgrade the memory and if still its not working then this might be malware issue.

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Last weeks question "Why is my cpu running at ....."

In reply to: Troubleshooting a slow PC

The link in the preferred answer "Troubleshooting a slow PC "
-- Submitted by: Droid" Takes me to "Content not foundPage Not Found
We're sorry, but the page you requested could not be found. Please check your typing and try again,
or use the search options on this page." Both of the referred sites sound like they would be very useful, can you check and if possible respond with working sites. Thanks you for taking the time to provide solutions to CNET user.
Bob Smith

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Why is my pc running at 100% when...

In reply to: Troubleshooting a slow PC

Many thanks for taking the trouble to look at my problem.I have just under 1Gb of physical memory(RAM) and before I consider an upgrade, I want to explore other suggestions that have been made.
Kind regards

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Troubleshooting slow PC

In reply to: Troubleshooting a slow PC

My PC, (emachineT3422) had come to a complete halt. The fan was running constantly. My son in law ( simple took off the back of the computer, and cleaned the fan with a microsoft cloth. The fan had a quarter inch of visible dirt and dust on it. The computer runs like new now. He wanted to use a blower, but I didn't have a blower. The cloth did the trick. I offer this suggestion to those with a similar problem.

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CPU running at 100 percent

Dear Patrick,
There could be some reason's:
1.Your low on Physical memory, the RAM memory?! how much do you have? you can find it: *RT click on your taskbar, Select "Task Manager"
* Select "performance" tab
*look for the " Physical memory"
If you have below 1GB= not good at all
If you have below 2GB= not good enough
If you have between 3-4 GB= nice
if you have over 4GB= very good
2.Once a year maybe twice it is recommended to install ,from the Start, your Operating System.
3.Never the less you must consider a newer computer in case yours is old let's say over 3-4 years.

Doron-Andy Brill
Pardess-Hanna Karkur

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CPU running at 100%

In reply to: CPU running at 100 percent

Dear Doron

Very many thanks for your time and suggestions on how to fix my problem. It appears that I fail to meet the first criterion that you suggested:my pc only has 981,488Kb of physical memory(RAM)! I shall therefore check through the other suggestions and if all else fails will consider an upgrade.

Kind regards

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Not necessarily that its an old computer...

In reply to: CPU running at 100 percent

My old XP computer is around 4 years old, AND it has 2GB Ram and an AMD Sempron 1.8GHz Processor. I have not had a lot of problems with CPU running at 100% under normal use (3 windows open) I think what this user needs to do is definately look at other running processes. thats is programs and processes running in the background, these run at startup. Click - Start>Run and type in msconfig in the window, then have a look at all the programs running at start-up, generally you do not need them all running, but be careful with what you un-click. Also the next step is to do a defrag at startup, as a defrag using windows defragger after windows has started doesnt always do a complete defrag.

Heres how:

1. Launch the Registry Editor (Regedit.exe).
2. Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce.
3. Right-click the RunOnce subkey and select New and select String Value.
4. In the "Value" text field type Defrag and press [Enter] twice.
5. Type Defrag.exe c: /f in the Value Data text box, and click OK.
6. Close the Registry Editor and restart Windows.
7. When windows restarts, the system will boot to the Desktop but no tools
No Icons, no Taskbar will be visible however a Command window will be.

How long this takes Depends on how badly fragmented your drive is like normal.
While this is running there will be no Taskbar, no Desktop Icons, and therefore no ability to do anything else. How long it takes depends on how badly fragged you drive is. Failing all that yes a full format and fresh re-install is a good idea, dont forget to backup your files though. OH and a HD running at more than 75% full will cause a lot of problems. Get a Bigger HD and partition it 360Gb plus is a good size.

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Maybe is a virus program running on your computer. Try to scan entire your computer with up to date antivirus.

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Why is my CPU running at 100 percent

This can be a number of things.

1: Anti virus or anti spyware program doing a background scan. But I would be very surprised if even though you had one of these doing a background scan that your PC was maxing out at 100 percent, especially if your PC is not that old. Have you opened up the task manager by holding at the same time the following keys CTRL ALT DEL (sometimes labelled DELETE) and checking what processes are using a large amount of the CPU power?

2: You may have too many programs running when you computer starts up or one program you have running is not running properly and causing the high CPU usage, or some programs you have running when your computer starts up, are perhaps interfering with another and causing the high CPU usage.

3: Or it could be that your PC is old and is severely struggling to run what you are asking it too. How old is your PC?

I used to have a PC that would for no reason whatsoever hit 100 percent and then become unresponsive. I'm sure that in the end up I found it to be a driver issue.

Does your PC hit 100 percent on a regular basis, or can you pinpoint something that you start to do on your PC that starts the 100 percent CPU usage?

For the time being, I would access your computers startup, by loading msconfig, and click on the GENERAL tab, and select the DIAGNOSTIC STARTUP, which basically only loads up basic devices and services needed to load Windows.

After you have done this, see if the 100 percent CPU usage stops away, if it does then its some program you have running when your PC starts up. If this is the case, then enable a startup entry that has been previously deselected (BUT ONLY ENABLE ONE AT A TIME), restart your PC and test to see if the 100 percent CPU usage reappears. Keep doing this (MAKE SURE YOU RESTART YOUR PC AFTER YOU ENABLE A STARTUP ENTRY) until you see the 100 percent CPU usage problem reappear. When you do, remember what the last thing was that you enabled in the startup, and that will tell you which program has been the cause of the 100 percent CPU usage problem.

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CPU running at 100%

In reply to: Why is my CPU running at 100 percent

Hi and thank you for your help and time in suggesting solutions to my problem. I followed the diagnostic course you suggested and found there were 28 startup programs on the system.Following your instructions, I was able to eliminate 15 with the result that the surge to 100% disappeared.The other observation I have made is that the surge seems to occur when I use either of the two browsers I have-perhaps it would also make sense to use just one brower.

Thank you once again for helping me.

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I've experienced the same problem with Windows XP, and would like to note that i dont even have Internet and a nirus entered my system! Watch your external hard drives that you are plugging in, there is a virus that makes use of svchost.exe to use up most of your memory. SVCHOST may be a Windows process, but as microsoft say, it is ?a generic host process name for services that run from dynamic-link libraries?. In english?

Some time ago, Microsoft started moving all of the functionality from internal Windows services into .dll files instead of .exe files. From a programming perspective this makes more sense for reusability? but the problem is that you can?t launch a .dll file directly from Windows, it has to be loaded up from a running executable (.exe). Thus the svchost.exe process was born. And thats also when virus creators became "creative".

What you can do is recall when you installed some software or plugged in an HDD recently,and Restore it to another state. Else a Full format would be necessary. If you run a full virus scan it may be lengthly and might corrupt Windows entirely, which will bring you back to Formatting, so skip the virus scan!!

Ahmed, South Africa

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This is the worst I had once

In reply to: SVCHOST Maybe

Once I Had a problem with the SVCHOST slowing down my PC. Practically I was unable to do anything. A friend of mine suggested to reformat the hard disk if possible. An online virus check detected some malacious softwares too.
It solved my problem. Now I take care of my PC limiting all my
family members to use only through the limited account( no Administrative rights)
Wish you all a great week end.

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"Why is my CPU running at 100 percent

In reply to: This is the worst I had once

If you want to save time, just restore your computer as it was when you bought it.This is my way to solve these kind of issues.
It is the fastest approach w/ 100% success. The memory could matter, but because you did not experiment this kind of troubles before is less probable.

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Windows error files are a plague to me.

In reply to: "Why is my CPU running at 100 percent

I'm with Mil Shield.

My rating for CCleaner is not so good because this tool has not so many features that other tools as MilShield have (for example profiles cleaning, regedit history cleaning, dom storage cleaning). I was looking for Vista searches cleaning and then found Mil Shield. Windows error files too.

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Yes You Right

In reply to: SVCHOST Maybe

MaCafee just sent out with one of their security updates a virus along with it. Collapsed ever computer that was using MaCafee. I use Norton and still got the Personal Security virus which was a major job getting rid of it. It was in my programs downloads as well as my registry. The best one can do is watch everything they open or download. I use an external HD but, knock on wood, I have not got a virus through it. I mainly use it for photos and some minor applications downloads. I run a disc cleanup and defrag on a daily basis because I have the time to do those as well as do a regular checkup on what is actually in my registry and recent updates!!

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I have the same problem at times. I have learnt to live with it. Although frustrating just let it work its own way out over a few minutes, and then all's back to normal. Cheers, Bob.

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To many programs

I had the same problem . It was enough to uninstall 6 programs . It is preferably to use an uninstall program like Revo Uninstaller (free).
This way all remains are also cleaned .

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CPU running at 100% XP

I have had this problem too and couldn't fully identify the problem. However it is worth noting that the processes under lsass.exe have been known to be compromised and I would suggest running process explorer from sys internals:
This should be able to show you what is going on in more detail. Try shutting down processes one by one to identify the culprit. Also from sys internal run rootkit revealer to check if you have a rootkit virus.

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In reply to: CPU running at 100% XP

In my case ,I also had cpu running 100%.
Wondering what was going on. My p.c. win xp.
I opened task manager, and played with the processes tab, but that did not help. Last year I purchased an external hard drive, that I would connect to my xp or vista pc.
Vista pc cpu was normal, when using external hard drive.
But when task manager was opened in xp, with cpu 100%, I disconnected the external hard drive, and instantly brought down the cpu usage to normal.
Hope this helps. I also believe that if the pc is getting old like my xp, pushing 7 years old, nothing will help. The processor and chip set built in, have done their time. Keeping your pc for simple browsing is ok, but don't ask it to do to much.

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Why is Windows running at 100 percent

I have had similar problems with anti-virus programs and also Adobe programs. Open up Task Manager (Cntl-Alt-Del), and click on the Processes tab. If you can identify the process that's running excessively, try to find out whether or not you really need it active. Perhaps you can end the process with Task Manager, then remove it from the Startup list to solve the problem. If it's a virus, then you may have to go into Safe Mode to get rid of it.

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This is why your cpu is running an excessive percent

In reply to: Why is Windows running at 100 percent

Forget the virus and too many programs open... its not the ram or cpu characteristic. zombie programs? HOGWASH.... i will assure you my suggestion will fix your problem... i have fixed dozens of computers with this problem and it will fix yours, too... if your cpu shows more than 20 percent activity with no programs open then your power supply is defective... thats right, your power supply.. the components in your ps get hot and age... the ability of the ps capacitors to filter ripples and spikes on the output voltages decline with age... these ripples and spikes show up at the cpu as trigger pulses, turning your cpu on and off at these pulse frequencies... change your power supply and presto, your problem will be gone... use at least a 500 watt ps, and if you have more than one hard drive use a 650 or 750 watt ps....btw, i havent seen this fix anywhere else, it took me weeks of trial and error to fix the first one, and it has fixed everyone since then.. if you replace your ps with a new one and still have the problem, i want to hear about it,

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use a 650 or 750 watt ps....btw,

In reply to: This is why your cpu is running an excessive percent

QUOTE: and if you have more than one hard drive use a 650 or 750 watt ps....btw,

Hi anyonecom,
I also get 100% spikes but not all the time, and as I have 3 HDD's an 80Gb with the OS, A 40Gb with games installed, and a 250Gb storage drive.
It does look like I could have the prob that you have highlighted,
so for the less savvy of us can you tell us where we 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?
Sorry to be a pain, but we are not all boffins Happy

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