Welcome to Fusion forum. Which kind of USB superdrive did you use?
As mentioned in my initial post, it's an Apple USB Superdrive. A generic drive works, but the Apple one does not, or works sporadically. Seems to me that Win 7 does not have the right driver for it, but no idea how to get it.....
Has this issue been resolved or discussed any further?
I see this thread has not been added to for some time. But I have just had exactly this same problem and found several similar discussion threads elsewhere where nobody has an answer. I then found the following procedure worked fine for me:
1) Powered my Mac down and rebooted (I was "frozen" from a previous unsuccessful approach with the superdrive). I did not reboot the Windows virtual machine.
2) Connected the Superdrive, which was automatically connected to Mac OS. It appeared as a drive and was recognised by its name. I inserted a CD that was read and left it in the drive.
3) Open the VMWare Fusion library and the settings panel for the virtual machine (Windows 10 in my case).
4) Click on "Add Device" in the top right corner and select CD/DVD Drive. This produces a box with a drop-down list for selecting the drive. The Superdrive was already preselected by name, but even if it had not been I think it would have been possible to select it using Finder.
5) Started the virtual machine and the Superdrive was connected and was reading the inserted disk, which I was then able to access and use.