This is how you fix the no disk error in norton.
When you open norton ghost and it begins to connect you get the error. Keep clicking the cancel tab until it disappears. Then go to TASKS--->MANAGE BACKUP DESTINATION. When the backup destinations appear you will see one that has either been deleted(the program will tell you so) or one where there is no longer a disk letter(you may have backed up to this letter previously and it no longer exhists due to a hardware change). DELETE THIS RECOVERY POINT. You can also go into TASKS--->OPTIONS-->GENERAL and make sure your default backup location is a real drive location.
This has worked completely for me using norton ghost 12. I believe that it will also work (if the options are similar) in other versions of ghost.