Computer Freeze

So I recently installed Lego Star Wars II, and it seems I can only play it for a couple of minutes.  Around the 7 minute mark of playing (it's not the game, as I can actually progress if i save correctly) there's a "VOOSH" sound that comes from the inside of my tower.  It's the sound of something shutting off.  The game goes on to play for a couple more seconds, the computer still runs... but then it completely freezes, and I have to hard-reset.  Any ideas?  Something overheating?  What could it be?  How can i fix?

Anyone?  Perhaps I need a heatsink?  Any tips for installation?  Am I wrong?

It only happens with that game?

Maybe is a lack of power supply, and it just stops. Or overheating.

Try other games, and tell us

Well, "VOOSH" is pretty broad.

You should start with getting the newest driver and firnware for everything possible, maybe they already fixed this thing.

Or you could open the box, and see what has stopped. And check the temperatures when you reboot.