Restarts while playin games

I have an intel 865 gbf motherboard and an nvidia 6600gt.my computer restarts while playin games.pls help.?

i have a 400W powersafe power supply,512MB ram(hynix).i have 4 fans in the system.ive even got the card replaced.the computer restarts or the game crashes to desktop(happens with all games).pleeeeeeeeeease help me.i m highly frustrated.

Additional Details

somebody suggested that the 6600gt is not compatble with the 865 gbf.ive tried running it on a friend's 865 gbm.it worked fine.does gbf and gbm make that much of a difference?

Solution:-

I had the same problem and my graphics card was overclocked call where you bought it if you have warenty if not bring it to a shop shop

Source(s):
i have a web site i now of but it man not help you that much but try www.tomshardware.com good info on computer stuff