weird XP boot-up problem

[dTak]

my friend's computer turns on for 5 seconds and it turns off randomly.

sometimes when he screws around with the bios settings, it turns on.

it's a 90% change the computer will turn off, and a 10% chance it stays on.

what do you think is the problem?

since it turns on once in a while, heat really shouldn't be the problem right?

they never opened the computer before. No configurations had been made

[Digitalic]

Power supply or motherboard problem pops up in my mind from the info you are providing.

However, at what point before, during or after the POST does it shutdown?

[PommieB]

Theres definately an hardware problem, try another power supply and reduce your setup to a minimum, more info would be better.