you may need to partition then format yer drive.
with win9x, in the start menu click on "run..." then type fdisk.
i think its option 4 to viewavailable drives. you need to change to yer raid then create a primary partition, then after you restart it will be in my computer and you can format it and yer right to go.
if ya got win XP goto computer management in administrative tools and there is a disk manager there to partition the disc.