In your BIOS - What is the boot order set to? Can the BIOS identify the make/model of the CD drive?
I can recommend investigating a boot from USB flash drive option. Maybe use Linux as a testbed.
If he was running a system from the last decade, I would explore that possibility, but I am not sure he can get access to Linux, and with a CD Drive that was running on a windows 98 machine...the machine is at minimum 10 years old...it's a good possibility the drive is just bad.