U have to set up RAID in BIOS, check motherboard manual. I would never rely on RAID0 for storage, if one hard drive fails, you loose ALL data. RAID0 is good for working with video files, but to keep them safe, NO-NO!
Partition that 500 gig drive, let's say 50 gig for Windows and programs and the rest for backup or other data. That way if windows need reinstall, you don't loose data.
I would also put pagefile on RAID0 array.