Vista install hangs after entering license key

Hello all,

I've got an XP Pro machine that I'm upgrading to Vista Ultimate. When I run
setup it gets to the page where I enter the license key, and I enter it and
click Next. (This is during the "collecting information" phase of
installation.) At that point it hangs with a wait cursor. In task manager I
can see one (of three) setup.exes running one core (of this dual-core
processor) at 100%, doing no I/Os, with no change in memory usage. (The next
page would be the EULA page, but it never gets that far.)

Some internet searching has lead me to find others who have encountered this
problem, but I haven't found a solution. For example, these two links seem to
exactly describe my situation:

http://winvistaforums.com/windows-vi...y-trouble.html

http://www.vistax64.com/vista-genera...formation.html

I have tried booting into safe mode and running install from there, same
problem. I also did an XP repair (to ensure that I didn't have any corrupt XP
OS files), but the problem persists. Disconnecting the network doesn't seem
to have any bearing either.

Ideas?

Thanks everyone!