From somebody who's been there, done that (twice) and now my kids want it (2
more installs) - here's my approach. You want a dual-boot setup (i.e. XP on
C: and Vista on a new partition. You need to create a new partition of at
least 30GB (although MS recommends 40GB). Name that partition Vista RC1 (or
whatever). Now, boot up and go into XP. Put in your .iso burned Vista in
the DVD drive AND INSTALL FROM WITHIN XP. If you don't install within XP,
you have the potential of losing your drive letter assignments, and XP
itself. Choose "custom" install - NOT upgrade. Choosing the custom install
will propmpt you for which drive you want to install it on. Choose the
partition you just created (i.e. x:Vista RC1). Enter your key, and you
should be good to go. Allow plenty of time (at least an hour or more), and
DO not shut down, turn off, or anything. There will be times you think
things aren't working. But you should see the 3 little dots moving during
the copy/expand stage, and your screen may even go blank. Your PC will also
re-boot several times. Again, let the install do the work. So far I'm
liking RC1. It's much more stable than beta-2, and Internet access is
blazingly fast. Good luck, and post your expiriences/horrors.