Does your PC see your Nook?
only by sound. Will it be visible when I go my Computer?
If it isn't then ADE won't be able to see your nook.
This the best script I have found when you can't load a library book on to a NOOK Glowlight when using a Mac:
How to transfer eBooks to a NOOK GlowLight Plus
The NOOK GlowLight Plus natively supports EPUBs and PDFs. This means you don't need to transfer eBooks through Adobe Digital Editions (ADE) onto your eReader. While you don't need ADE to transfer, you do need ADE to download the eBooks onto your computer before you transfer them.
Use the steps below to transfer eBooks to your NOOK GlowLight Plus:
1 Authorize your NOOK GlowLight Plus with an Adobe ID (find instructions under "How do I transfer and read Adobe DRM ePub and PDF files?").
2 Plug your NOOK GlowLight Plus into your computer using a USB cable.
3 Note: If you're using a Mac computer, you'll need to install Android File Transfer so your GlowLight Plus will be recognized by your computer and you can transfer eBooks to it.
4 On your Windows or Mac computer, download a borrowed eBook to ADE.
5 Right-click the eBook in ADE and click Show File in Explorer (Windows) or Show File in Finder (Mac).
6 Drag the eBook file from the folder that opens to the My Files folder of your NOOK. Your NOOK will appear as a removable device in the left-hand side of the Explorer or Finder window.
8 Disconnect your NOOK from your computer.
You'll find the newly transferred eBook on your NOOK under Library > My Files.
Works for me every time.