Not sure which forum to post this but When i start up the machine it does post and everything is normal but then when it goes to the black Win XP load screen it does that for a few seconds then restarts. and just keeps repeating over and over again. Its not software because I tried the HDD off my machine in it and it does same thing, Iv tried a diff stick of ram, All fans are running. I cant think of anything else. Also sometimes right before it restarts i notice a Blue Screen But it goes by so fast i cant even read a letter.

Windows XP (and 2000 for that matter) require that you use the same motherboard as when you first installed the OS. That means testing a working windows from your working computer in a questionable computer will just fail while attempting to load windows. As for the rest of the question, sometimes windows will restart instead of displaying the BSOD. You'll almost definately just have to reinstall XP on your non-working machine.

Try enabling the blue screen, so you can actually know what is causing your problem... Start->Control Panel->System->Advanced->StartUp and Recovery->Settings->. Then under "System Failure" uncheck "Automatically restart".