MBP Restarts while logging onto Windows (Boot Camp)

[Keopx]

Hi, just yesterday i was using Windows XP SP2 on my MacBook Pro with Boot Camp... and by today's morning when i turned it on, the keyboard didn't respond at all, and couldn't log onto Windows... later i got a USB keyboard so i could enter my login password... did it, but when Windows starts loading, MBP sudenly goes black and restarts... what i did then was login onto Mac OS, made a backup of my Windows partition data, deleted my Windows partition with Boot Camp assistant and started a new Windows installation... completed it and inserted the Leopard disc to install the Boot Camp drivers for Windows, when it finished installing, it requested for a restart... restarted, logged onto Windows and ohhh boy... MBP goes black and restarts again... ... has anyone experienced this problem?, can anyone give me an advice on what i could try to solve the problem?... i'm really worried about this problem, i hope you Mac gurus can help me out!... thanks in advance!!