"Setup is being restarted" loop...

I just bought a piece-together pc from an online vendor. Everything
went smoothly on the physical assembly. But I ran into a problem when
I went to install XP Pro. Setup was completed (or so it seemed) and
the pc rebooted itself. On startup it displayed a light blue screen
with the message "setup is being restarted." No reason or description
listed. And, just as it said, setup started from the beginning. It
will do this over and over and over. I tried reformatting... ran HD
utilities (10 hours of burn-in tests)... tested the memory... tried
an older XP Home disk... removed any unnecessary peripherals... And
it will still "restart" setup each and every time. Can anyone point
me in the right direction? All the thanks in the world!

Have you check the power supply unit?
Have you check the temp. of the cpu (touch the heatsink, is it
very hot) ?

[AssassinateZ]

You have to open up the computer and pull out a battery which is a circle silver battery.