adding windows xp to a laptop with a RAID 0

Can anyone advise me how to add Windows xp to my laptop that CAN be configured to a raid? It seems to me that as soon as I convert the two matched drives (one of them having xp installed on it) to raid 0, The set up to raid 0 will erase the OS. that is already installed and cause a crash. Any advice would be very welcome. Peter Smith