Library books to my Nook

I am now using windows 10 - prior to this windows 8 and no problem.  I am unable to transfer library books to my nook. Both my nook and cmputer are registered.   I switched to adobe 3.0 and stillno luck.  I have installed and uninstalled the program and still can't transfer.  Called Barnes and Noble and they were no hlep  Can anyone assist me.  I have been trying to do this for the last 4 hours.  Thanks.