CPU usage 100% constantly

I just reinstalled XP Pro and all programs are working, but the machine is running noticably slower than before. I haven't loaded any new programs that weren't there before the reinstall. However, Task Manager shows 100% CPU usage with no apps open. I suspended everything that was memory resident with no effect. Is there a way to determine what is causing the usage? Short of uninstalling programs one at a time, I don't know how to proceed.
While attempting to load Adobe Flash 9, I got an error message saying that I didn't have enough free disk space: free up 5000KB and try again. Windows shows 62 GB free on my hard drive, and I have 1 GB ram with 66% free. I hope somebody can tell me what's going on. I ran Spybot which showed two minor problems that I deleted. I did a virus scan with avast! which was clean. A subsequent reboot changed nothing.

 

Svchost.exe is the culprit using 6144K of memory, but there are 9 instances of this program listed some of which use more memory.

 

Pete C, Thanks for your prompt and accurate reply. My problem is solved. I downloaded and ran Windows Process Explorer. It told me that my HP 7460 printer software was using all the CPU time looking for updates. Once I killed that handle the computer runs like it always did. I don't know why it would be an issue now as I installed the printer several months ago, long before the XP reload. I'll check the HP software to make sure it doesn't run again.

This is twice in the last week that windowsbbs.com has saved my bacon. You guys are the best!

 

100% Cpu

A possibility is that either Ad-Aware or Acrobat updaters never complete and either could be at the root of your problem. If you run either please advise and I'll try a detail a fix.