Maximum PC

Ok guys, I have a question. Rebuilt by old i7 920 into a backup rig. specs are:

i7 920
ASUS P6T Deluxe V2
6GB Corsair RAM
(2) EVGA 260 Video cards
Silverstone 850W PS

This thing ran rock solid for 1.5 years as my primary rig. Now it randomly restarts. Sometimes it will do it when it is folding, sometimes sitting at the desktop, sometimes in firefox. I can run Memtest on it all day without problems. I ran Prime95 for 14 hours with no errors and highest CPU core temp 65 degrees. The PS tests good. Any ideas? Could my install of WinXP have some problem that would cause this? The only difference between when it was my main rig and now is then I had a Soundblaster in it and now I use onboard sound. I have never seen random restarts like this. Not lockups, just a hard reboot. Thanks...

atr

Did you completely remove the driver for the Soundblaster sound card before switching to the onboard sound and installing the drivers for it?

1. Start in safe mode
2. Go to Control Panel -> Administrative Tools -> Event Viewer -> (Left pane) Windows Logs\System.

See if there's anything weird in there regarding failures or something.

It was a fresh install of Windows, the SB drivers were never in this install.

I didn't see anything there. And it's not locking up, just restarting. The other weird thing is that when I'm running the GPU folding sometimes the CPU side will get so slow that it will take 30 seconds or so for the cursor to move to match the mouse, and it will remain jumpy for minutes at a time. I'm starting to think the PS is failing under load. It tests good, but of course that isn't under any load at all. I replaced it with a spare PCP&C 750 watt model and am running it for a while to see...

atr