I have a Compaq desktop running XP MCE that exhibits the following behavior
1) "System" uses 100% of the cpu even while ide, Used Process Explorer.
2) The USB ports go dead when in Windows. For example, a usb optical mouse will light up during boot, but once Windows starts running, the USB goes dark and no light on the mouse
I've tried the following:
Found and removed 30+ viruses (yes, it belongs to a teenager) using NIS 2011, ComboFix, and Housecall.
Ran sfc /scannow
Un-installed and re-installed the USB drivers
Any suggestions? Could it be a rogue device driver?