SPECS: Asus A7N8X AMD xp3000+ 1gb Corsair PC3200 XMS LL ATI 9800 pro ? Geforce 7800 GS OC Maxtor 120gb SATA Antek TruePower 480 Audigy 2 Problem History: Computer began restarting during active periods in windows over a week ago. 3dmark 03, 05, and 06 all freeze during load of or near start of tests (tests sometimes render normally for 20 sec before freezing) -Causes non-recoverable crash, no error reporting, PSU must flipped -Windows was reformatted and the ATI 9800 was upgraded to an AGP Geforce 7800 GS OC. - All drivers are up to date, bios up to date, mobo drivers up to date, raid as well - windows is also fully updated -Tried multiple driver versions for raid, and many graphics drivers - Still getting random restarts every hour or so and 3dmark has same problem. -Ram was checked using windows ram diag and mem86 (5 passes) - errors found under two tests (10ish total) -isolated sticks via removing one at a time -one stick found to be the only one defective -booted computer with the good piece of ram and tried 3dmark 03, and 05 -this failed as usual and my computer still restarts when in windows - tried installing a game (F.E.A.R) to test but could not finish without restart Conclusions: -The ram sectors that are not matching are not the cause since the computer was booted with the single stick of good ram and problem persisted. -PSU could be the problem? Rails under PC Probe look tight however… -Motherboard? -CPU? -HD? Any suggestions would be greatly appreciated!. Thanks for all of your help.