Longhorn and vista do a image install, there is no point to formatting your drive. It also uses WinFS, not NTFS or FAT16/32, you wont find a dos boot disk that can format a drive for it. But you would not have a problem if you weren't using some cobbled together pir8 version.
If you go to the lan I have a bootable floppy image as well as a CD and USB image that will help you, let me know and I'll pack it.