ASUS M3A78-T MOBO

When storage configuration on mobo is set to IDE I have no issue running my Window XP Floppy OS Boot Disk to run FDISK, Format c:, and install windows OS. However, when I set storage configuartion to RAID or AHCI, my boot disk gets me to DOS prompt but I cannot see my Optical Drive or Hard Drive. When I switch back to IDE mode everything works again. Please help.... frustrating.... Is it the CD1.sys driver on the boot disk that needs to be replaced with different .sys ?? I even tried the Magic boot disk but it did not work either. Any help is appreciated.

I don't know much about these hard drive thingies, but wouldn't you need a driver for the RAID? Also, I've heard that you have to actually set up a RAID, not just switch from regular mode to super-duper RAID mode.

I'm just dumb about these things. Could you explain what you're trying to do?