CPU usage with no associated process

[codename47]

In the last week my computer has a phantom 25-30% cpu usage that I can't seem to track down. It causes the computer to stutter and the mouse to jump from point to point. It is consistent no matter if it is just started or have been running for hours. I've looked in the processes screen and sorted by useage but nothing ever pops up that is taking over 2%. It has made the system unuseable pretty much.

I tried to restore from a previous date and that didn't correct the issue. I've ran multiple virus and spyware scans using avast, lavasoft, and spybot with no findings.

Any ideas as to how to figure out what is using so much cpu? My last resort is just reinstalling the OS but I'd rather not...

 

[defaultluser]

Sounds like a nasty virus.

If you're infected and the malware is particularly nasty, it could hide itself from even the best scanners. After my first experience with a kernel-exploit virus/trojan (8 hours of misery trying to remove it), I've just assumed the machine would have to be wiped clean.

It's even possible that the system restore is not helping because the virus is telling the OS that the files are unchanged, or it's preventing the OS from overwriting infected files. Once malware has kernel-level access, there's not much you can do.

 

[codename47]

Well I'm guessing it was a nasty virus or some malware b/c it ate my antivirus program last night so I just reloaded windows... now I'm doing a full scan of the backed up files to make sure they aren't infected.... really sucks but at the same time a refresh never hurts b/c it feels like a new PC again I usually try one every year and this one was due. The PC is back to its usual self.