I have been using ADE with Nook for years with books downloaded from our library.
I have purchased a book from B&N and cannot put it through ADE as the authorization info does not match the DRM info which is my wife's B&N account info.
I tried uninstalling and reinstalling ADE but it will not release the original authorization info which is me.
How can I change that info? At this rate I will not be able to buy books on this computer!
To remove the authorization you need to hit ctrl-shift-D while in ADE library view. (cmd-shift-D on Mac).
One of those essential features ADE likes to keep hidden from its users.