Bustem' Down
Give Peas a Chance
Ok, try this: Open the Task Manager and select the Performance tab. Leave it open. When the PC "freezes", check the display and see if the CPU has gone to 90% or more. If yes, and it doesn't show up in the Processes tab, you may have a system service that has gone nutz or more likely, some malware (virus, adware, spyware...). If no, you may have a hardware problem. If you have a diagnostic disk, you can run extensive diagnostics overnight.
Yep, it froze and then showed 100%. Seen it randomly bounce up to 81% and 94% but only froze at 100%. The only process that shows numbers this high is System Idle Processes.