I am unable to authorise ADE with my adobe account on a different computer

[Guest]

Here is the message I get when I try tried to authorise ADE with my Adobe account on a different computer.

I receive a message saying :

You can only authorise this computer with an Adobe ID that hasn't been previously used to authorise any other computer or mobile devices. Please try again.

The information provided on the authroisation window says that my Adobe ID can be used to authorise up to six computers or devices.

Please help!

[Nanaky]

Windows:

    Close all applications.

    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

    Select the Adept key.

    Choose File > Export.

    In the Export Registry File dialog box, select Selected Branch under Export Range. Enter a name and location for the backup registry key, and then click Save.

    Right-click the Adept key and choose Delete.

    In the Confirm Key Delete dialog, click OK.

    Close the Registry Editor.

    Open Adobe Digital Editions and reauthorize.

Macintosh:

    quit Adobe Digital Editions.

    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 https://helpx.adobe.com/x-productkb/global/access-hidden-user-library-files.html

    Open Adobe Digital Editions and reauthorize.