[Lil`one]

Hi...I have a computer that just will not work! We've taken the whole thing apart and put it back together again, and all we can get out of it is that it'll start up until the Windows XP boot screen, and then it just begins to reboot and reboot, and reboot. We've tried all of the hardware that we can think of to take out and then put back in, stripped the computer to it's barest bones and even then it still won't run. We've ruled out the video, sound, memory, and hard drives, and just can't think of anything else to try! Is there anything we can do?

Thanks for all the help in advance!!!