More Windows Vista Install Problems - Help me please?

I've received a disk from Microsoft (I ordered it rather than downloaded
given the installation problems listed here). I tried to install it on two
computers, basically state of the art brand new dual core Dell's with more
than enough power to run Vista. On both systems, after the install begins
and Vista looks for updates on the internet, it states that it can't get an
internet connection (even though it is connected). I "ignore" the updates,
finish the install, it seems to go to the very end in each case, but on the
final re-boot it reverses the install and goes back to XP for some reason.

How broken is this version? Does anybody have any suggestions for me?