You need to configure VirtualBox to see the CD drive as if it were its own.

Virtual machines don't always connect to the resources on your actual computer unless you tell them to. A few of them it does, for example I think the LAN connection is one that VirtualBox enables by default, but otherwise, things like USB devices and CD-ROM drives, by default it doesn't connect to them until you explicitly tell it to do so.

In your screen shot, where it says "Storage", I only see the virtual hard disk, not the CD-ROM drive. That's probably the issue.

Somewhere in the VirtualBox configuration will be a place for it to configure its virtual CD-ROM drive. It will be named something like "Devices" or something like that. And you will select some menu or button with a name similar to "Add Device" or somesuch. Once you've done that and selected that you want to add a CD-ROM to the virtual machine, then, there will be some kind of a choice where you get to choose what to put INTO that CD-ROM drive. You can choose to:

- Tell it to look at an ISO image file, and pretend the contents of that ISO image file are its CD-ROM drive. (an ISO image is like a single-file rip of an entire CD in one file on the hard disk.)

- Or, tell it to look at the computer's actual CD-ROM drive and use that as its CD-ROM drive.

In your case, you want the latter, since, you don't have an ISO image file of that CD, you have the actual CD.

I'm not sure, but also I seem to recall that if you want to use the CD drive in your real operating system (windows 8) then you have to disconnect/deconfigure the virtual machine using it. (The guest OS and the host OS can't use it at the same time). I could be wrong about that part, though, maybe they'll work together just fine.