I have a Dell Dimension 9100 that just started to keep rebooting after the XP Logo.
It is a SATA hard drive, and I am unable to get a BSOD STOP code, even when disabling the Automatic Reboot upon SYstem Failure (f8). Oddly, I tried bootinbg off a known working SATA hard drive, and it did the same thing. I took the hard drive in this machine, and booted from it in another machine and it came up. Also tried replacing RAM, changed the SATA Cables, and reseated the power cables.
On the software side of things, I tried doing a repair install and it did not see the hard drive!
When trying Safe Mode the system gets to MUP.SYS and then restarts. This happens even with another HD.
Finally, I replaced everything - memory, video card, monitor, keyboard, mouse, BIOS (also removed BIOS battery), power supply, you name it. Nothing worked to get out of the reboot loop. I then ordered a new mother board from Dell and even with every component changed out - including the hard drive, I get the same problem.
I know the software is good because the HD boots when I slip it into another machine.
Could it be that the Rerfurb MB that Dell shipped me has exactly the same problem that my original one had and that I just need to get a new one?