This may help.
I am not familiar with this board, but there should be no reason why it should not boot from one SATA drive.
You say that you have installed X\P. Is it up and running or are you still in the set up mode. I see that you have installed the raid drivers, did you take these from the motherboard installation disk? Were it says copy to diskette.
Also have you installed the SATA drivers from the hard disk manufactures web site, when loading the O\S?