Create a bootable floppy with your RAID drivers.
Boot into the RAID BIOS, and set up your array.
Insert the windows disc.
Boot into the motherboard BIOS, and set the CD/DVD drive as the first boot device. Make sure to save the changes, and exit.
On restart, press a key when prompted.
When the disc starts to load, you'll see a prompt at the bottom for F6 to load 3rd party drivers. Insert the floppy, and press F6 to load the RAID drivers.
When finished, windows will continue to install on the array.