UDMA in Win98 for CDRW

[Ordo]

Okay, I just put together a system for a friend that form some reason won't allow me to enable DMA mode for the DVD drive or the CDRW drive. The option isn't even available in the properties tab in the system settings. Could it be that the system is not using Win98SE? He insisted that I re-install his old OS from his CD.

Here are the important specs:
Asus CUSL2 (with current updates)
Pioneer DVD-105s(slot loading-not SCSI)
Plexwriter 12/10/32
IBM Deskstar 45 GB (that has DMA enabled)
Win98 (not SE)

Help!!! Thanks in advance.