I swapped my core 2 duo for a quad core recently, and generally things run fine, but every now and then my computer just restarts. I don't even get a blue screen (Vista 32).

Core temp isn't a problem.

My thinking is that my power supply is inadequate, but I haven't been able to test that (one idea was to under clock the cpu to see if that helped, but going up in speed was the only simple thing to do in the BIOS)

Two cases where I semi-consistanly get problems: - Borderlands windowed after some period of time (and some other games, but Borderlands does it pretty regularly) - watching a video (e.g. quicktime/vlc) and having another video running

Another thought is non-cpu heat? Maybe the graphics card?

Any thoughts on how to track this down appreciated.

Thanks!