go to Fdisk using a Win 98 or ME Floppy disk.
When in FDISK press option 4 and display your partitions.
Choose 3 & Delete 4
Then choose 4 and check all and no partitions are there.
Then select 1 Create new Primary Doss partition.
Validate is Y and Y when asked by the way.
Reboot (Change the Boot order to CD & HDD then have your XP CD in CD when it starts to search for booting from CD prese enter and follow onscreen prompt.
When asked to format in FAT or NTFS choose NTFS (not quick)