MyBook unsucessfull backup response?

Attached MyBook external drive auto backup to new computer.  No option from My Book icon for setup.exe but

seems connected anyway.   backing up Win 7 computer.  Starts backup from Control Panel - Backup & Restore.

After about 35mins, it stops backup and says “unsuccessful” but no error details. Have tried with firewall disabled too.

Backup was working OK on 1st computer.  $t is plenty of memory.  Any ideas on why it won’t complete backup now?  

Thanks     

Hello, You seem to be using Windows backup to backup your files. Can you share the model number for your hard drive?