New Motherboard XP repair keeps rebooting

I have done many in place xp repairs when installing new motherboards. This one is puzzling and I am looking for advice. THe repair install did its initial install however when XP reboots to complete the installation the splash screen appears and the system reboots. I have several complete backups of the c: drive so data recovery is not an issue. I would like to get this installed without doing a fresh install.

After the repair failed I installed a spare hard drive that I was able to do complete a fresh install of XP with this new equipment. THat would indicate to me there is something wrong with the repaired drive. Tonight I am restoring a back up and will try the repair process again. I ran memtest with no issues. Any ideas on how to troubleshoot this? I cannot get into safe mode as the install is not yet completed. I am assuming the XP repair install takes care of hardware issues with the new equipment. Also, I have tbe bare minimum hooked up at the moment, i.e. video card, hard drive cd drivei. One last item.....My XP Pro was patched to sp3 but my install cd was only included sp2. I am also making a slipstream copy with sp3 to try tomorrow. Any ideas a re appreciated. Many thanks,

Steve