Windows 98???

I have two older computers at work that have windows 98 on them. I have a CAD program that runs on 98 that I want to use the computer for. My problem is windows is not recognizing the cd drives in the computer and I don't have the original 98 Disk because that is what came with the computer. There is nothing I need on the computer but would like to have 98 on it so I can run this older program. Any suggestions?