If you’re having trouble authorizing your NOOK device with Adobe Digital Editions:
1. Plug the device in to the computer via USB.
2. Open Adobe Digital Editions (ADE).
CTRL + SHIFT + E (Windows)
CMD + SHIFT + E (Mac)
3. Unplug your NOOK and then plug it back it in. The Device Setup Assistant should start up again and give you the option to Authorize your Device.
After you authorize it, you should be able to drag and drop books from your ADE library to the Nook.