BSOD 101 or game crashes durring any high end game

I've been haveing some trouble with either game crashes or full bluescreen (error 101). I WAS useing twin GeForce 9600GTs in SLI, I recently upgraded to a HD 7870. The problem did not change, suggesting that video drivers are not the source... Although altering the drivers with the 9600GTs did seem to effect if the game crashed or full bluescreen crash. So basicly, the PC works fine untill I...