You don't use Dell Datasafe for backups to your own external drive. Use Windows Backup and Restore instead. Read THIS. Dell Datasafe is for Online Storage.
I bought the upgrade of Dell Datasafe and am trying to change the backup location for local backups to a network drive. I have a 2 terabyte drive (so plenty of room is available) connected to my network which appears in Windows Explorer and which I can access there.  But it will not appear in Dell Datasafe. I have tried the refresh button, but it still is hidden. How do I make this recognized.  This is the reason I spent the extra money for the upgrade.  Thanks.  
Dell Datasafe local backup can't find network drive