Using My Book Live for a home network backup

For the first problem. ((( I’m a newbie so maybe you should double check this))) The one on the desktop I believe is a shortcut and just delete it.  The one under My Computer you can right click it and choose “Disconnect”. I read in Windows where Windows assigns network drive letters Z to A and internal drive letters A to Z. So I kept the Z. Again ask someone to verify this.

The second problem I don’t know, I’m just learning this stuff myself.