Hi,
Enter in BIOS (by pressing Del or F2 or F10 or Whatever) and create a fresh RAID array from there (it will be under SATA configuration option) after you have configured a new array, prompt for over writing the existing volume. After you are through, keep an array driver floppy ready and start loading XP, press F6 and insert the floppy.
BOL

but do know that in the striped array or any RAID array for that matter, you are supposed to see just one volume.
Also let me know if it worked or not