I've been experiencing the titular issue on just about every 3d game I own. After some variable amount of time played in nearly any game, the screen locks black, the sound stutters, and I am forced to hard reboot. The amount of time this takes is variable and varies from game to game. Minecraft typically crashes within 10 minutes. WoW can crash after 20 minutes, or after 4 hours, or not at all. Alpha Protocol crashes after some splash screens.

I initially suspected this to be a heat issue, but after monitoring temperatures while gaming I don't think that could be possible. After some extended gaming the max temperature of my video card at -max- hit 75C and typically ran rather lower. (Minecraft crashed with it running at 65C.) The CPU didn't exceed 61C.

I shifted my focus to software and installed a fresh copy of Windows--formerly I had been running Vista and figured this was as good an excuse as any to upgrade to 7 (an upgrade sorely needed -despite- the crashy-crashy). So I backed up my files and reinstalled some programs and still experience the same crashes on WoW and Minecraft, and I imagine other games would result in the same deal.

After a fresh install (not doing -Upgrade-, but the -Custom-) the Registry must have been clear of the sorts of demons that cause these crashes, so I imagine the issue must lie in hardware somewhere. (Power supply?) Any ideas?

My machine is a laptop, a Qosmio with
an Intel core2 duo @ 2.0 Ghz
an Nvidia Geforce 9700M GTS
and 4 gig of RAM
on (as of today!) 64-bit Windows 7 Professional

Let me know if any other information can help.