I've searched the forums for similar problems, and didn't find anything. Apologies if the ANSWER does exist!

Anytime I play a GAME the system locks up, and it happens anywhere from several hours to a few minutes after starting the game, including 3-D games that are 6 years old. I have a few games I've never been able to play on this system because they'll hard crash the system before I even make it past their splash screens.

Athlon XP 5200+ w/ liquid cooling
2 GB RAM
2x 233 GB hard drives in RAID 0
1x 233 GB backup
DVD/CD RW
nVidia Geforce 9500GT 1GB (350 Watt, powered from motherboard and not directly from PS)
Extra video card fan
500 watt power supply
Windows Vista SP1


What I've tried so far:

All drivers and bios current
Complete format/reinstall
replaced 400 watt, direct to PS geforce 8800 with the 350 watt 9500 (originally thought it was a power/heat issue. System's definitely cooler with the new card, though)
Added the video card case fan
Chaning CPU affinity to 1 CPU core
Changing system priority
Changing program compatibility from Vista to XP

Case thermometer consistently reads 27 C
CPU running at 54 C (~20 less than MAXIMUM)
8800 ran well below max temp, as does the current 9500

I'm at my wits end... I bought the system to play games, but right now it's just a big paper WEIGHT. Much obliged for any help you can provide!

try using OLDER versions of nForce drivers.Quote

CPU running at 54 C

try using older versions of nForce drivers.

Idle, or while gaming?