If the motherboard doesn't have that selection, you will have to load the raid drivers (but don't set up the raid). I set up a wierd combo for a guy a year ago that had the hard drive, CD ROM, CD Writer, and a Zip drive using all four slots. Works like a charm and the Zip drive doesn't slow down the hard drive bacause it's on it's own cable. I did have to move some drive letters around for him in Windows though.
About a month ago he wanted to try Windows XP Pro (originally we put SE on it) so I set up his hard drive to dual boot. Still works like a charm.