Good afternoon all, My computer crashes irregularly when playing 3d games. It could happen after 15 minutes, or after 90 minutes, or never after 3 hours. My computer is: AMD Sempron 2800+ Biostar 6100-M7 mobo 2gb ram (1gb x 2) Nvidia 6800gs video card The computer will reboot itself while playing 3d games, specifically: BF 2 Homeworld 2 Civilization 4 Video card & mobo drivers/bios are the latest. I used ramtest 1.86 and was 0 errors over 10 passes (12 hours) Also I've run a lot of anti-virus/anti-spyware and found nothing. I replaced the video card (used to be 6600gt) and added the 2nd gig of memory, with no change. Can someone help me locate the problem? thanks!