Computer boots but then loses video and sound

Hello,

I recently just purchased a new video card and I installed it myself. After doing multiple tests and what not I decided to run some games on it. I will boot into the game and it will load fine as per normal, however around 6 minutes in the video will suddenly die and sound just stops. I have CPU-Z open when it happens and my video card is at 40C and my CPU is around 60C (all 4 cores of my Q6600). Does anyone know anything I can try to pinpoint the problem since I can't really see anything when the monitor goes out?

Thanks,

Scott