Crashing During Steam Games

I'm not sure what's up with my PC, but when I play games that I downloaded from Steam (Dead Space, F.E.A.R.) the screen will freeze with what I can only describe as "rainbow static" and then hard-reset.

This is confusing because all my drivers are up to date, my temps are fine, and the games are fairly old. The PC plays WoW and SCII totally fine on very high graphics settings so I'm not sure what the problem may be. Any help is much appreciated.

GPU dying or clogged with dust.

The gpu being clogged with dust can't be it (or overheating) because I've blown them out, checked temps, and it still plays MUCH more intensive games like SCII like a dream. At least I'm not the only one experiencing this!