MY BOOK 1 TB ESSENTIAL - Doesn't work on my new computer

After succefully installing my new My Book Essential 1TB on my old PC, I cannot get it to backup on my new computer.  I have spent over an hour on phone with WD’s Level 2 support people… removed the password, reinstalled the unit etc.  No luck.  Has anybody had this experience and found a solution please? 

This may be a dumb question, but since SmartWare will only back up the current user’s files (and All Users), are you sure that the Windows user for the files you’re trying to back up is the exact same user you’re currently logged into Windows as?

If the files are from a different computer, than even if the user name is the same, Windows will see it as a different user.

Does changing the ownership of the files you’re trying to back up to your current Windows user make a difference?

(  Right-click the C:/Users/User Name folder and select “Properties”.  Click the “Security” tab.  Click “Advanced”.  Click the “Owner” tab.  Click “Edit”.  “Change owner to:” and select your current user in the selection box, and check the “Replace owner on subcontainers and objects” box and then click “Ok” and wait while it changes all your files. )

Even doing a clean install of Windows on the same computer, let alone different computers, I’ve had Windows tell me those aren’t my files and I don’t have permission to access them, despite the user names being the same… but the internal coding has different numbers for the users and they’re not the “same”.