I have a new computer. I can get the ebooks from the library into Digital Editions but I cannot get it onto my Nook. It says that it doesn't have permission to copy it, but I can do it on my old computer. I went through the authorization process and made sure my Barnes and Noble account is the same email and password as my Adobe account.
You need to have the same Adobe account active on the new computer and the Nook.
I don't think it matters what the B&N account is for library books.
It sounds as if you must have had the same Adobe account on the old computer and the Nook,
and I assume you have used that same account yet again to authorize ADE on the new computer?
So, it should work. One possibility is that ADE got its authorization screwed up on the new computer, see below.
If that doesn't help, post back with any more details you can think of.
Sometimes ADE gets its registration/activation confused and in a semi-authorized state.
Uninstalling and reinstalling does not help, and indeed installation can even trigger this state.
Unfortunately, it often then gives misleading error messages about what is wrong.
A common incorrect message informs you that the ID is already in use on another computer and cannot be reused.
Another is "E_AUTH_NOT_READY"
This can often be resolved by completely removing any authorization using ctrl-shift-D to the Library screen on ADE (cmd-shift-D if on Mac).
Restart ADE, and then reauthorize with your (old) Adobe ID.
In extreme cases on the mac, the following extra step has helped some people. Navigate to /Users//Library/Application Support/Adobe/Digital Editions and drag the activation.dat file to the trash. If you are using 10.7, see Access hidden user library files | Mac OS 10.7 Lion. http://forums.adobe.com/thread/1265248?tstart=0