Creating a RAID-5 after Server 2003 is installed

I'm building a server for my school and I'm having some RAID issues. The "server" is an Intel Q9550 on a Asus Maximus II Formula motherboard with 8GB of Corsair RAM. I have Server 2003 installed on a 250GB Seagate HD hooked into the "speeding HD" port on the motherboard and 4 750GB WD HD's plugged into the Intel ICH10R ports on the motherboard. What I'm trying to do is make a RAID-5 with the 4 750GB HD's. I believe I installed the RAID drivers when I installed Windows but I'm not that confident that it worked. When I looked in the ASUS handbook it said there would be an option to enable RAID in the BIOS but I cannot find it. Is it possible for me to reinstall the RAID drivers without reinstalling Windows or is there something else I should do? I know you can do like a software RAID in windows but I wanted to use the chipset to do the RAID-5.
Thank-You in advance.