JUST did a clean install of XP Pro and I am having the exact same problem
that caused me to do the install. If I have ANY USB devices installed, XP
won't boot. I have four on board USB boards, 2 more PCI cards with 4 each for
a total of 12. I can't seem to locate any updated drivers. Uninstalling and
re-sinstalling the USB drivers doesn't work.

I've tried it with all kind sof combinations of devices and there doesn't
seem to be a common thread. MoBo, power supply, memory, HD are all fine. All
bought within a year.

Any ideas?