Microsoft’s Backup/Restore

I have a client who is using Microsoft Backoffcie Small Business Server v4.5. They do a backup each evening. Now they need to restore a few files, but are unable to because there does not appear to be a catalog on the tape. I have run the catalogoption and it did not find any catalog entries. So the Question – Is there a way to to get the tape to read its self and create a new catalog. Remember they are using the built in Microsoft Backup option.

TIA for any suggestions.