If using IDE, you can install XP first then create RAID 0. If using hardware RAID, use the driver and software that came with your MB or RAID card. XP Pro can do software RAID 0 without hardware, but slower because of the additional software overhead.
If you have SATA, good luck, because the only easiest solution is to copy your RAID/SATA driver to a floppy. Try searching for it on the MB CD or Manufacture site.