I once had a DVD drive that was giving me fits trying to install on a friend's computer. It actually turned out to be some kind of driver issue, but I can't remember exactly what it was. Seems like it was with a file named SCSI???? (something or other) even though it's an IDE drive. Sorry I can't be more specific.
As for the sound problem, you should be able to use digital sound instead of analog and do without the audio cable to the sound card. Find your CD or DVD drive in the Device Manager, find this screen in the properties, and check the "Enable digital..." box. Of course this won't help until Windows recognizes the drive.
Good luck!