Any time my computer uses 50+% of its CPU for more than a few minutes, the power to my USB ports seems to be shut off, and then the CPU spikes to 100% and stays there. (syncing my iPhone is what was causing the 50% load)
The only thing installed is MS Security Essentials (real time scanned is turned off), and iTunes. It is a fresh install of Win 7 from 3 days ago. I guess it could be a virus, but I doubt it considering the OS is fresh, and the PC hasn't been used much.
I have never seen anything like this happen before, and am at a loss as to what would cause it. I could just re-format again, but I would like to solve the problem. Anybody have any thoughts?
If it matters, the general specs are 2.7ghz dual core with 4gb ram.
edit: I didn't mean that suggest it was iTunes, I was just pointing out what was causing the load. I have seen it happen with the system under load and iTunes wasn't running. I'll try prime95 tonight and see what happens.
Also, let me point out again that the cpu is only under 50% load when this happens. the fact that it jumps to 100 is a symptom, no?
edit: I formatted the drive and started from scratch. Running prim95 has no effect on it. However, I installed iTunes and the symptoms appear. Maybe it is iTunes. Any other ideas? Let me also add that nothing is in the event log.
edit: As far as I can tell the PSU does not have enough power to charge the iphone, run the wireless adapter, and the CPU at full speed. I think power to the USB is being shut off so the rest of the system gets enough. (does that make sense?) If so, I would mark molly's point about the PSU being insufficient as the answer, however it is a comment. If you make it an answer I'll accept it. :)