I have run ad-aware, norton antivirus, spybot-search and destroy, hijackthis, and the system is clean.
Normally (at boot time) I have mysql, pgptray, an ftp file server, norton antivirus, itouch (keyboard driver), yamaha softsynth, creative labs webcam go control panel, running in the taskbar, but when I close all these programs down, and just have the system processes running, (services.exe, spoolsv.exe, 5 instances of svhost.exe, system, winlogon.exe, and system idle process), the system idle process still shows 95% cpu usage, services.exe flucuated between 20-28%, then the system idle process drops to 80%, but even that's high, taskmgr only uses about 2%, all others use 0% until executed.
I tried doing a system restart, then executed paint, then watched the cpu usage, system idle shot to 100% and there was a problem with using paint, but when I closed paint, system idle process dropped to 95%.
I checked with a friends computer running the same xp pro, but with 128Mb ram, he has plenty on the taskbar, his system idle process fluctuated between 20-30%