Apparently your friend using old hardware, cuz I have Vista on my laptop, and several members here use Vista as their main OS and it works fine. Vista 64bit is much more compatible with things than XP 64bit is, BTW.Vista is the future ,LOL, maybe windows 7. A friend of mine has vista and its a piece of junk, there are so many driver incompatibility's. All i have to say is windows xp 64bit, or windows server 2003, is the way to go for now, wait tell windows 7 comes out, maybe then i'll upgrade.
sorry for my rant, its coming from experience, vista is just not worth it.
i recently upgraded to windows xp pro 64bit due to the limitations of the x86 version. It gave me nothing but trouble, ever since i upgraded to the sli 4gb duel channel memory, that is.