I recently have restored my Windows 8.1 system to a new disk. Few days ago I installed Digital Editions 3.0 because I had bought a book for wich ADE was mandatory . There was no problem reading the book with my Adobe ID. At that point in time I had not yet activated my Windows 8.1 license. . After reactivating my license I suddenly got e_act_NOT_ready errors.
I followed the Adobe's instructions , removed the activation and also removed the ADEPT key from the registry. After that I got ' Document not licensed for this device'.
I restored a backup of the OS which was not yet activated and could read the book again.
I am looking for a way to get around this without buying a new ebook license(which was quite expensive by the way).