I want to install Vista home premium on my SR 2.4 MBP that has 4 gb ram using Bootcamp. I would install it to an external Passport drive that connects to the MBP with USB. Is there any benefit or drawback to installing the 32 bit or 64 bit version of Vista on a MBP that can only have 4 gb ram? Will I have problems installing my Windows software that works on XP 32 bit on Vista 32 bit or 64 bit? I'm thinking of MS Office, Adobe master collection and Poser 6 as the software I plan to install. Thanks for any advice.