The microsoft site has two utilities, one for XP Home and one for XP Pro that allow you to build a boot disk set from your installation )(ends up with six disks I think). You still need a cd with XP on it to complete the install. Running setup from disk one allows you various options. Alternatively, If you still have a ME or 98 boot disk, with FDISK on it, set the bios to boot through a floppy first, then boot to your old disk. Run FDISK to delete the XP Partition, then recreate and format to your hearts content