Before you do too much more, check the "Recycle Bin" in Windows Explorer and see if there are any files there that end with either .dvr or .dll.

It sounds as though your CD-R and DVD drivers have been deleted.

Each of those drives will normally require a driver installation for the Win98 system to recognize them. (The "driver" is just a small program that tells your computer how to run the drive.) You should have at least a "recovery" or "installation" CD from Dell that you can use to get them back, or separate disks from the mfrs if the drives were added after you got the machine, if that's the problem.

There's also the possibility that you've lost an internal connection, so take a look and see if any lights come on, and/or if you can hear the drives spin if you put a disk in.

John