You'll need the client storage manager. For the English version you can get it here:
When you install the stoage manager software it will "configure" the system for operation. Part of this will be to ask if you want the included Retrospect software installed and to map the Backups and public drives to the client system. Not having the drives mapped is ususally what causes the issue of not having a disk drive to store data.
The client storage manager provides greater detail than with generic browser access. The storage manager browser information is received from the Client Web-Server and the Device Web-Server. If generic browser used, information from Client Web-Server (AppWeb) is not available.