That's a fine clue that the machine overheated or the power supply became overtaxed. Correct that and you may fix it.
I have had relatively few problems with my home PC which runs Windows XP and 1 GB of Ram, however, recently I upgraded my 32 MB video card to one which has 128 MB and which runs significantly faster than the previous one.
I had no problems with this upgrade, however as of recent, if I try to burn two or more DVDs (backups of my key files) or if I even try to watch a DVD movie on the computer, the system will shut down - just power off.
It will then not restart for a good 3 to 5 minutes. I unplug everything, wait a few minutes and then try, and finally after some time, it will turn back on again.
Any idea what could be causing this to occur as it is extremely annoying.