computer shutting down/help??

[subra]

it has happened 2x now, i'm just on the internet just reading & all of a sudden the computer has shut down, i could not start it with the start button. what i did was unplug the plug at the back of the case & replug it & it will start when i hit the start button.
Does anyone have any suggestions what would cause this problem?

thx for the help

 

[0roo0roo]

take a power supply from another comp and use that for a while to test.