Have you activated/registered/authorized it?
First, authorize your copy of ADE with an Adobe account/ID (menu/Help/Authorize Computer to ADE)
Authorizing without Adobe ID (I forget the term they use will not do, it must be authorized with your Adobe ID).
Then, with the Nook plugged in and ADE running, (menu/Help/Authorize Device to ADE)
I authorized my nook and it still tells me that I don't have permission to copy books from ADE on my PC to my nook