I am working on an HP desktop that came to me with XP Media Center Edition installed and was updated to SP2. I tried to install SP3 (both through Automatic Updates and manually) and have run into a problem. It all seemed to go well, but won't reboot properly. If I just let it boot to normal mode, it starts to load Windows, shows the Windows logo, then reboots. I am able to reboot to either Safe Mode, though.
I have tried disabling everything in Services and in Startup through MSConfig (including Microsoft items) with the same result.
I have scanned for viruses and spyware with Norton, Housecall, SuperAntiSpyware, Malwarebytes, and TDSSKiller. None found anything significant.
I ran Memtest for a number of passes and found no RAM errors.
I have tested the hard drive with chkdsk /f and with the manufacturer's diags with no errors found.
I have run sfc /scannow with no problems found.
I don't have a suitable copy of MCE to use for a repair install.
The computer had Norton 360 on it, which I have uninstalled (before another SP3 try) with no change.
Any suggestions on how to proceed would be appreciated. I don't want to have to give this back without SP3 installed if I can avoid it.