Did you receive a driver disc with your MB? That should include the RAID drivers you need. When you install Windows for the first time it will say something like "press F7 or F8" or something" to install 3rd party SATA drivers.
Also, you need to make sure that SATA and RAID are both enabled in your bios.
This manual from DFI's website should help you regarding the Nvida RAID drivers:
<a href=\"http://www.democracynow.org\"><img src=\"http://i5.photobucket.com/albums/y165/smileygladhands/linkbanner468x60.gif\" border=\"0\"></a>
\"All over the place, from the popular culture to the propaganda system, there is constant pressure to make people feel that they are helpless, that the only role they can have is to ratify decisions and to consume.\" -Noam Chomsky