I'm upgrading to a heat sync video card and that for sure will help.
I also did clean my pc inside and that foo was dusty, like SUPER dusty!
I been playing CoD MW 4, FarCry2 and no shut down, so I pretty much think it's solved.

Not sure yet, going to play assassin's creed II and see what happens, if it shuts down then, not sure what to do, besides upgrading my video card.