hi,
In this case, the drives are okay, u will not need to replace them. If this is an HP computer then u can visit this link,
http://h10025.www1.hp.com/ewfrf/wc/genericDocument?docname=c01068864&cc=us&dlc=en&lc=en&jumpid=reg_R1002_USEN and can download the patch and also try the steps.
Tf this does not help, then we will have to erase the raid configuration completely and re-set it up on the pc.
For that would like to know if you are using the windows xp or vista and if the raid is set up using the Nvidia MediaShield or is it Intel Matrix Storage. ?
Do let me if this helps ?