If a database is stored on a CD-ROM, it cannot be deleted in the conventional sense, but rather has to be unregistered. A CD database should always be unregistered before removing/disconnecting the storage medium it is on.
To unregister a CD database
Select the CD database that you want to unregister and choose from the context menu. The Confirm Unregister CD Database page appears.
Choose to unregister the CD database.
