Installed 3M cloud library and can't remove the authorization from ADE

I still have ADE 3.0 (for Windows) installed on my PC. I was able to deauthorize using 3.0 (using ctrl-shift-D to deauthorize in 3.0 doesn't require a username and password) -- Then I could re-authorize 4.0 w/ my AdobeID. Hope this helps.

I found another possible solution from this thread: Re: unable to erase authorization

Mac:
Navigate to /Users//Library/Application Support/Adobe/Digital Editions and drag the activation.dat file to the trash.
ADE will be deauthorized now.
Now Authorize ADE again.

Windows:
Choose Start > Run.
In the Open text box, type regedit and then press Enter. The Registry Editor opens.
In the left pane of the Registry Editor, locate the following registry key:
HKEY_CURRENT_USER\Software\Adobe\Adept
Right-click the Adept key and choose Delete.
In the Confirm Key Delete dialog, click OK.

Your authorization will be deleted.
ADE will be deauthorized now.
Now Authorize ADE again.