Computer Hardware erroring out on OS installation?

From my experience,you're overlooking the obvious culprit, which would be the cd or dvd drive itself.I've had problems as you describe before when trying to install xp,switched out the cd drive and problem solved.You may not have gotten an error message when you installed vista, but that doesn't mean it installed correctly.I've had power supplies die before and they never affected any other hardware.You said the computer would crash when a cd was in the drive,I'd check the power cable and cable from the mobo to the cd or dvd drive and/or replace the drive.