I have one too!
The routine is:
Set BIOS to "Promise controller active" (Advanced on board devices)
A new dialogue comes up. Choose RAID or IDE - beware, once you have
installed the drivers it is a nightmare going back!
Save, exit, and reboot.
Be sure your new disk is freshly formatted. Install WinXP and when it
asks you to press F6 and give it the drivers, put in your floppy (made
with Makedisk exe) for RAID or IDE as you wish. That's it!
Now I have a system from an oem who pre installed the os so I cannot
do this install. Also I changed my mind and want JBOD IDE not RAID.
ASUS will not help as the system is oem. The oem will not help because
I did not specify the disk not buy it from them. So if anyone knows
how to reinstall the Promise driver on this Mobo I'd love to hear. At
the moment I have to force reinstallation of the IDE driver at every
re boot, which is a royal pain!