I really don't have a clue about these 64 bit and 86 bit operating systems. But if I remember correctly, Leopard is supposedly 64bit? Therefore it should run Vista x64 perfectly off VMWare Fusion? Any possibility of x86 running on the 2.2 Macbook? Is there any difference between 64 and 86? I have 4GB ram in my 2.2 Macbook, is it wise to run Vista off VMWare Fusion? 4GB is obviously a lot, but would it still be slow? Is XP the better choice?