Computer crashes while playing video games

Hello,

I play a number of video games, but only the graphically demanding ones seem to crash my computer. I bought a Geforce 9600 GT not too long ago, and i had the latest drivers for it when it started crashing. I continued to update the display drivers as they were released, but I still found myself with the same problem. Thinking it was my power supply, as the old one had a dismally low wattage rating, I picked up a 700 watt power supply. The minimum wattage requirement for the Geforce 9600 GT is 400 watts. As you may have guessed, my purchase was in vain.

Hi

Question... does the computer restart or shut down? I wonder... is your computer free from dust? i seem to remember my old computer would shut down with higher end graphic games and all i had to do was clean the dust out of certain key areas (like the CPU)