Is My Power Supply Going Bad?

[Warhammer]

A few weeks or so ago, I downloaded the Supreme Commander Demo, installed it, and started playing. After about 20 minutes, my system just shut down. Initially, I thought everything was overheating due to be overloaded, and the system did not start up again immediately.

I uninstalled the demo, and was going to defrag the hard drive (a few days after the previous event). The defrag starts, and then suddenly, I lose my D: drive. The system just stops recognizing it. I stop the process, shut down the computer, and then restart it, and the MB starts up in safe mode.

I figure it might be the D: drive and decide to do a complete check of the drive which turns up negative.

I get IL 2 1946, install it, and as a game that shouldn't tax my system start it up. Suddenly, my machine fails. Black screen, everything shuts down. I try to start the system up again, and it starts and then stops. After waiting about 3 minutes, I give it another go and get everything up, but again the MB loads into safe mode.

Is this all caused by my Power supply going bad? I checked the diagnostics in the BIOS, and most of the leads are roughtly .05 V under what they should be. I don't know what else to check, but find it peculiar that everytime I strain the system, something fails, but if I just check email, play unintensive games, etc. that everything is fine.

[Airhog]

I would say it is either your video card, hard drive or your memory

[Peregrine]

I've had a failing power supply before, and the symptoms were always like the first one, restarts, especially during intensive games. The other symptoms could be a video card or other option.