When I start the computer it boots and in the XP welcome screen it restarts. I have narrowed the porblem down to my graphics card Abit Geforce2 T400, I have tried to start it with my second card Ati Radeon VE and it goes into windows fine.
I have tried the card with AGP Aperture size 4M, then it works fine, but when I try anything higher than 4M the computer starts rebooting. Now i'm not sure whether it is an mobo error or videocard error, because even with the ATI Radeon, when I try to play Operation Flashpoint, it restarts. Other games are causing the computer to restart after about 5min of gameplay.