You've probably already tried this, but I had the same problem and found that I needed to connect my Nook, turn it on, then open ADE.
Don't try to delete the book from your computer copy of ADE. It appears
that you have to get ADE to recognize your Nook color. When it does, then
you'll see its icon on the left hand side of the screen when it's plugged
in. I have a different ereader, so I don't know the process for the Nook
color. Anyone else?
I think my problem is similar to many I'm seeing on the discussion board. In
ADE I can see and transfer books from the public library and they are listed
in the "Library" section of ADE so I can drop them into the Nook. However,
books from free sites when downloaded open in ADE in reading mode but can't
be located in the "Library" in ADE so even though the Nook is recognized and
icon shows in ADE I can't get it on the Nook through ADE. On reading other
threads of the discussion, I've found a convoluted way to get those books on
my Nook. I have a MAC. I had to do a "Find" for the title of the free book
that was in my downloads folder (I can't drag and drop from the downloads
folder). When the results show up in the "Find" window I can drag the title
from there to my Nook and then put the title in the "Digital Editions"
folder on the Nook. It works, but is seems as though those books should
transfer as easily as the ones from the "Library2Go" site from the public
library. Thank you for note.
Translated to a PC:
Use Windows Explorer to locate the book by title. Then use one of the
methods available to put it in the Digital Editions folder. Then, open ADE
and use the 'Add Book' function in the Library window to get ADE to
Methods available on the PC include drag and drop or 'cut and paste' and
'move to folder' commands.
Hope this helps (and works for you!)
I experience the identical fail with my Nook Color and ADE V.4.x
No problem loading library books into ADE on my Win7 laptop. I can read them there no problem.
But when I connect my Nook, ADE does not recognize it as a device, even though my laptop does.
Workaround so far has been to locate the files in Windows Explorer, then open a separate window for the Nook and navigate to:
Computer>MyNOOK>Internal Storage>My Files>Books
(I could find no "digital editions" folder on my Nook)
Then drag and drop the desired ePUB files.
IMO Adobe has delivered a rather poor user experience in this instance and should fix it.
I cannot find the Nook icon in ADE to drag my public library book to my Nook Glowlight. I have done it many times, but today it is not showing at all.