You need to get the CDROM drive detected in the bios first.  Make sure the drive is jumpered to the cable select position and not master or slave.  Put it on the secondary IDE cable on the connector furthest from the motherboard.  Then reset the NVRAM and go into the bios.  Check it is detected correctly before going into the OS.

Absolutely, like peter said. i might add I've had lots of GX1 experience and have had this happen lots of times. The GX1 BIOS isn't very dynamic. Some versions of GX1 don't autodetect drives very well. Usually, you have to go into the BIOS and manually tell it to autodetect, then double-check to make certain it populates the drive parameters.

 

If it's already detected in the BIOS OK, then it's a harder problem, and may require Registry editing and/or CDRW software upgrade.