Firstly, I should warn you that using an old installation of Windows on a new motherboard is generally a bad idea. Sometimes it works, sometimes it doesn't, and even after a repair install people are sometimes left to fix activation / driver problems. I would certainly recommend reinstalling Windows altogether.
Now, if you insist on using your old installation... what RAID are you using? 0, 1, or something else? If you have RAID 1, the contents of the drives are going to be identical so you can pretty much boot off either disc, you aren't required to have them in RAID to boot; boot off a single drive, see if it works and if your installation works just set them up in RAID again. If you have RAID 0... well, can't help you there.
