Problem seeing RAID array after install

I'm building a system for a friend,

MSI K9A2 Platinum motherboard AMD790FX
Athlon X2 6400+ 3.2Ghz
4GB Corsair 1066
150GB 10,000 RPM WD Raptor
Two 500GB Barracudas

anyway, there are 6 SATA ports on the MB and the last 2 are ' Promise T3 ', and apparently (i could be wrong) can only be used for a RAID array. This caused an issue when trying to hook up the 3 sata hard drives and the 2 sata DVD drives.

I figured " no big deal, I'll just plug the 2 barracudas into those sata ports and configure them as a RAID0 array, use them as storage, and install XP Pro on the raptor. " Defining the RAID ary was easy with the MSI FastBuild utility, but now after installing XP on the raptor, the system doesn't see the seagates.

I was told it is possible to have 1 drive stand alone and 2 others in RAID, but maybe I was misled. Maybe I overlooked a setting in the BIOS?? I don't even really want to run RAID, so if anyone knows a way to use the ' Promise T3 ' SATA ports as regular SATA ports, that would be great.

Any thoughts or suggestions would be greatly appreciated.

Thanks evongugg. RAID driver... boy do I feel stupid, i'll check the MSI CD for RAID drivers.