CPU constantly at 100% usage, even when computer is idle

Hello all.

Here's the problem: My CPU in my computer is constantly running at 100% usage, even when I'm doing nothing with my computer, and it's just sitting there.

Here's the system details:
CPU: Intel Pentium 4 2.80 Ghz
Memory: 4 GB
Operating System: Windows 7 Professional 32-bit
Video card: NVIDIA GeForce 7300 GT
Sound Card: SoundBlaster X-Fi Xtreme Audio

My thoughts as to the cause:
Looking at Windows Task Manager in the Processes tab shows me that rundll32.exe is the process that is hogging all the CPU power when other processes don't use it. I did a web search for this similar problem, and gathered that it's usually a fake, malicious rundll32.exe file, or a startup process that causes the problem. I have run all virus/spyware/malware scans as suggested by this forum, and found no problems. Then I ran a Hijack This scan and looked at all the startup processes, and have found none of them to be a widely known problem causer.

Interesting sidenote:
I'm not sure if this is normal or not, but Windows Task Manager shows two rundll32.exe processes. One of them is running under my username with the description "Windows host process (Rundll32)" and and uses 348K of RAM, the other one has the username SYSTEM with the same description and uses 1,048K of RAM. I also have 12 instances of svchost.exe running, each using various amounts of RAM with the users varying between LOCAL SERVICE, NETWORK SERVICE, and SYSTEM, but none of them are using very much CPU power.

 

the multiple svchost.exe are normal (i have 9 and they are always the same 9). the rundll32 is another matter (none running in mine) and might be a question for the experts in the Malware forum. they don't support HijackThis, here, so read the info in the stickies and maybe refer to this post via link if they don't move it in the meantime. they'll address your issues as soon as they can.

they have dedicated Malware experts here, so you'll definitely get the correct help you need.

 

It could be malware and from the symptoms your saying.

 

I have a notebook, running 2K, that does this and no it is not malware because the notebook rarely goes on the internet. I do get the windows updates directly from the MS site.

I have yet to figure out what causes the problem. For me, it is the services.exe that uses up most of the % so much so that windows never completely loads. I get no desktop icons because explorer never gets a chance to start.

The solution for me is to restore a previous image and then continue on.
It will be fine and then something again will cause the problem.

 

Try typing this in command prompt,it will write a text file that you can analyse

tasklist /m /fi "IMAGENAME eq rundll32.exe" >C:\rundll32.txt

You can locate the text file on your C drive C:\rundll32.txt

Now search through the modules for a clue as what its tryna run or running that causes the CPU to spike and try to disable the service.

http://windowsxp.mvps.org/rundll32.htm

 

Go to msconfig and disable the programs that you are not using, also the suspected program there is also a boot option that you set for 100% memory and the correct number of processors that you are using. Say for a dual core would be set for 2 instead of the default of 1 that was set on mine The difference in the performance and boot up time was amazing just from these two settings. You may have to do a system restore from the date before you started having the problem or Do a complete system clean restore and be sure to back up all your files to a web site or cds. Then Do a complete restore form the system restore that came with your system You can make a recovery disk if you dont already have one instructions are on your PC to create a System Restore cd This will take your PC back to when you first got it new so you will have to do all the windows updates It takes a while even on a cable modem So if you \can do a restore point that would be a better option It is always a good idea to do a full restore every couple of years or each year If you take your system in to s shop thay will charge you 200.00 to restore your PC but they will do all the windows updates They usally keep them on a cd I did when I had a business. So IF you cant resolve this the best advice I can give you is to do a full restore. It does sound like a virus Do you have a commerical Store Product Not a free one but something like Norton Anti Virus or Mc Affee That will get rid of a virus and you can avoid a restore of the system. I would install the antivirus program that you have after you do a complete system restore if that is your choice. It will fix the problem for sure.

 

There nothing wrong with Free anti virus programs such as AVG or Avast,they are often preferred over machine hogs such as Norton.

DO NOT do a system restore yet if you suspect its a virus,if it is a virus you may compound the problem,follow the readme's in the Malware forum first to the letter and ask them "nicely" to check your logs as there may be something your missing.

 

Yes I did forget to say that you need to remove the virus before you do a system restore.IF you have a good Virus program and there are some good shareware Virus and a few free ones But most of them do not get rid of a boot sector virus. Just make sure the Virus is gone before you do a restore. yes the restore will make your PC like it was when it was new. I just wanted to remind you to back up all your data and the windows updates if possible. That way when you do a restore and reinstall your Anti Virus program all the updates can be reinstalled maybe you can get a CD of the updates from someone that has a clean system That way you are not taking a chance of infecting your PC again. I would scan all your files after you get rid of the Virus to be sure before backing up your data.ms config will give you more control oof turning off the programs and services that are loading I agree with checking the logs for missed entrys. Then proceed with the restore after the viruus is gone and you have already tried turning off the programs that are loading There is a advanced tab in the Boot section of ms config Read the help section on ms config about these settings. The programs and services can be stoped from loading from here if you know which program is loading the dll file.

 

Thanks for all the help everyone! As it turns out, I solved the problem quite by accident. I ran Windows Update last night, and noticed there was a driver update for my video card. I tried once last week to try to install the update through Windows Update, but was unsuccessful, so I kind of postponed it for later since it was listed as a "recommended" update and not a critical one. I tried to install the update one more time through Windows update, and it was once again unsuccessful. I went to NVIDIA's official website to get the driver update manually, and installed it. After turning on the computer this morning and after it finished the install, I noticed the problem disappeared. Just like that. The problem was there since I installed Windows 7 in September, and now it's fixed. I assume it was due to an unsupported NVIDIA driver for Windows 7.