I think someone here might have the wrong end of the stick....
caffieneaddict.. are you booting from the vista DVD or installing from
within XP?
From within XP there is no option given to partition your drive, only
of where you want the installation to go, so you must already have
your partitions set up. If there is a way to do this i want to know
how...
Booting from the dvd i am under the impression that the options are
the same as for XP. You can create/delete partitions for
installation to, however you cannot resize existing ones. I have
also read on here that if you boot from the DVD then you might end up
with vista showing as installed on c:\, however when under XP vista
will show up on a different disk altogether. This may or may not
cause you problems.
The best way is to get hold of partitioning software such as
partition magic (and there are some free ones around as well but none
come to mind) and resize/set up the partitions before you start the
installation. If you do this, create a new Primary partition and
format it NTFS before you start the installation.