Make sure you've installed all the latest critical updates from Windows update. There's no chipset drivers available from Asus which means that the chipset should be supported by XP. Else the chipset in charge of the SATA controller is the SIS 964 chipset and you can find IDE and SATA drivers here :
http://www.sis.com/download/. Can't hurt to give them a try but start with Windows update.
Refer to the
motherboard manual to clear the BIOS settings (clear the RTC RAM in the manual).
What's the exact model of the hard drive and of the DVD drive ? Go to start => run and type devmgmt.msc. Expand disk drives and CD/DVD drives to find the model ID's.
While you're in the device manager check that there's no tagged device in the list (with a yellow or red icon).