Ok I just set my raptors in raid0. In order to do that I had to reinstal windows. So yes data will be lost. You must enable raid in bios, enable the sata ports that your hardrives are hooked up (Usually SATA_raid1 and SATA_RAID2) Then press CRTL-S or F4 or F10 to setup your raid however you want it. Make sure you make a boot disk for raid drivers (download it at ASUS site) Press F6 when windows installs and select the driver. From there you should be able to figure it out.
I dont know if theres a way to setup raid in windows.