I've been researching this problem hoping to find a solved but. But most instances don't apply to my exact situation. I just built a new rig. Specs:
Athlon 64 II 2.8GHZ QUAD.
2gb ddr3 memory master
I originally had 4gb of ram, but kept getting the infamous BSOD, and ended up being faulty stick. Just ordered 4more gig of same RAM but hasn't arrived yet. My 9600gt is from old comp, so I have reason to believe its not faulty, also latest driver from NVIDIA site. I can play games, for sometimes 30min or 5, and game will freeze. But not crash. I can alt tab out to windows. The problem really stumps me, I'm thinking RAM? Compatibility with the mboard maybe? I have no idea. Any advice would be appreciated.