Yesterday the download button was removed, with no notice, from user accounts on Barnes & Noble. This means you can no longer download your books directly to ADE & copy them into Calbre to remove the DRM. It appears Barnes & Noble wants you to read in one of 3 ways,
1) On a NOOK device.
2) In a NOOK app on another device or computer.
3) On the web in your browser.
The only books which still have the download option are the books which do not yet work with BN's read on web application. Once you can read a book online the download option will be removed. They essentially have to leave the download button for these titles, becuase if you don't have a NOOK device or app and you can't download then you would not be able to read at all, and they would probably have to give you a refund.
As for why they are doing this, it most likely has to do with customers using the loophole of social DRM to sideload eBooks on the NOOKs of family and friends. It is unknown if they decided to move in this direction on thier own, or some other entity is pushing them to close this loophole.
For the time being you can still access your books from the Nook for PC app. It is unknown as to how long this will be the case.
More info here
You are not allowed to view links.
If you are a Nook owner & have been relying on the BN website "My Nook" for storage I suggest you download the Nook for PC app for Win 2000 - Win 7 ( also works for Win
, or if you have upgraded to Win 8.1 the Nook Win 8 app (does not work with Win 8, only 8.1). That way you can still access your books & pull them into Calibre to de-DRM them. (I just tried it & that still works.)