Problem authorising second PC

[JS333]

2 days ago installed Adobe Digital Editions on my home desktop PC (Windows 7) and created Adobe ID (my email address) and a password to authorise this desktop PC.

Yesterday downloaded and installed Adobe Digital Editions on my laptop (Windows Vista) but without authorising the laptop.   It downloads books as expected.   I would now like to authorise the laptop.   I have clicked on Help/Authorize and continued to the authorisation page, entered the Adobe ID in the second space and the password in the lower space, and clicked on the “Authorize” button.   I get the message “You can only authorize this computer with an Adobe ID that hasn’t been previously used…..”    How do I authorise it?   I want to be able to download the same book onto both PCs when the book supplier permits this. 

[sjpt]

This is a standard and totally stupid wrong error message from ADE2.0.

Sometimes ADE gets its registration/activation confused and in a semi-authorized state.

Uninstalling and reinstalling does not help.

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.

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