In order to get rid of the extra screen you need to edit the boot.ini file to use
the /usenewloader at the end of the xp line. Then there are 2 files wininit and winload
that have to be copied from vista's system32 folder to the same in xp. That should
allow you to still dual boot and be able to get rid of that screen appearing twice.
Also as a note to MAC you can always get a copy of Vista by getting a MSDN subscription
and just downloading it, or knowing a freind with connections i suppose.
