either one is good. if you are upgrading a system to XP then you will have the option to stay fat or go ntfs, if the system is going to be new or home built and no os is installed XP will only allow ntfs. I have a fat32 40 GB hdd and a ntfs 40 gb ( poser is on the NTFS) and i have no real problems that i have seen. and i run the "Lesser" win2K pro