Emperus,Anort3and Pyree, thanks for the responses.
I have ran Mcafee, Registry Clean up, Disk Cleanup, Removed .avi files, quite a lot of .avi files would not allow me to remove them, emptied recycle bin, rebooted several times, ran file defrag and registry defrag.
It seems like some file in the Explorer.exe is causing this. As soon as I remove Explorer.exe the cpu goes back to 10, 20 % performance. Explorer.exe is using 80 to 90 % of cpu. Is there a tool to find the file that is causing it? I suspect it is a malware and probably is in the registry. This is a desktop and I have a Vista Premium Home addition with 2 Gig Ram, hard drive 133gb free of 232gb, 1300 Atheon Graphic card.