OK, and you just posted that you did exactly what I posted you should do. Never mind.
Did you apply all service packs?
Yeah, we did the Windows updates. It looks like the problem is due to Outlook 2000 relying on Outlook Express components, which Vista doesn’t have.
Tonight I got her set up with Thunderbird instead. It was a bit of a hassle getting everything imported from Outlook on the old computer, but it worked. :)