Look this is the main explanation:
FAT32: use for windows xp/2000
You can Read and wright
you can use Vmware fusion and parells
You can format with FAT32 when you have 32GB or less
NTFS: you have to use this for vista and for harddrive partions bigger then 32GB
You can only read form your mac side
You cant use parells or VMware Fusion
Q: so how do you have a vista bootcamp partion and run parells desktop or vmware fusion.
A:
YOU CANT