I'm playing Skyrim installed with DVD disk but it went through Steam in the installtion process for some reason. I'm guessing that's normal.
My OS is Windows 7 Home Professional 64 bit (OS is fully updated)
Intel Core i5 CPU 750 @ 2.67 GHz
4 Gig RAM
NVIDIA Gforce 500 series with updated drivers
Any help? I'm dead in the water here. I'm getting the same issue with Batman Arkham City by the way.

I've never heard power supply mentioned in quoting needed specs for a game.