put the Win XP disk in the cd-rom and change your boot up order so that it boots from your cd-rom first. when it boots up it will show a black screen with wrighting in the top left hand corner, when you see this press any key quick, follow it through, it will let you repartition then format in FAT32 or NTFS.
as to this> "format HD with current version of XP running". i dont know.
forgive me, im young. Jiggy