Computer is in infinite self reboot!

[nollen]

Custom built computer, bought with release of Windows XP. It shut down instantly with no warning on it's own and came back on in one second, only to be in a perpetual reboot cycle. It shows the main board scree, goes to a black screen with white type listing the options of what modes to restart in, then attempts to reboot, only to shut down about one second and then restart without getting to the desktop. Please help!

[Rob Pomeroy]

Strip your computer down to the barebones - one hard drive, one stick of memory, processor, graphics card, nothing else.  Does it then boot?

[Zylstra]

Strip your computer down to the barebones - one hard drive, one stick of memory, processor, graphics card, nothing else.  Does it then boot?

If there is a sticker labeled "Warranty Void if Broken" on your computer, do not open it. Bring it back, tell the manufacturer about the problem, and see if they can fix it.

(That is if you still have a warranty on it)