I believe that there is more to using the exfat file system than just replacing file system drivers, but I am guessing here, although I know a lot about exfat and the specification. First of all, it would be interesting to see how, after a xp system is built, how recycle bin would be handled since the directory entries are different as well as how deleted files are handled under exfat. Building an os on top of exfat, as well asvfat32 would be avail system without file permissions. Vista and windows 7 require the file permissions, so you can't build those systems on fat32 or exfat, but you are talking xp here, which still may be on fat32. Another issue is the boot sector, that is the VBR, which has a different format, and is 12 sectors, where in fat32 it is 3 sectors, and the bios parm block is different in the first sector. The exfat drivers might not handle this in xp. So an issue is if you could get some of the os to load, if you will succeed in booting it. I have yet to see any bootable code on an exfat drive, although I am interested to see itvwork
