Juan -

I took the computer into my campus computer offices, and among other things
we disable all third-party startup programs, plugged/unplugged it, and even
uninstalled a bunch of software. We did however find something very
interesting. The thread within Explorer.exe that was causing the problem was
ntdll.dll!RtlIntegerToUnicodeString+0x67
The tech guys told me that that means the function call is either being
repeated indefinitely, for some reason, or the function itself is looping,
for an equally unknown reason, because there was nothing but microsoft
software running after we were finished.
They suggested I try a "repair install" after trying everything else, so I
ran the "upgrade" install from my Vista disk again (since the only other
option it gave me was to re-format - not an option at the moment). This did
not fix the problem.

Any ideas?