Adobe Digital Editions is a piece of software that allow you to transfer e-books you borrowed from the library or another bookstore and allow you to transfer them to your e-reader, smartphone or tablet. Many people have been receiving a myriad of errors lately using older versions of Digital Editions. I would recommend anyone experiencing problems to upgrade to 2.01 or higher.
Over the course of the past few months Google Play, Overdrive and many other online retailers have updated their Adobe Content Server and this has created many problems with users who were using older versions of Adobe Digital Editions. I would recommend you use version 2.0.1 or 4.5, both seem to work.
Here are a series of tutorials that will safely deauthorize older versions of Digital Editions from your PC and make sure the new version works.
De-authorize Adobe Digital Editions from the Help command (if not possible, see later. I got an error on this step. Go ahead with the next step anyway)
Uninstall ADE from Control Panel – Programs & Features
Download and install the latest ADE 4.5 from the official link
If unable to remove old authorization, or re-authorize, follow these steps from this very helpful link
1. Quit Adobe Digital Editions.
2. Choose Start > Search for regedit (On Windows 10: it’s in c:\Windows directory)
3. Right click on regedit, ans select “Run as administrator”
4.In the left pane of the Registry Editor, locate the following registry key: HKEY_CURRENT_USER\Software\Adobe\Adept
5. Select “Adept” , right click on it and select “Delete”
6. In the Confirm Key Delete dialog, click OK.
7. Close the Registry Editor.
8. Open Adobe Digital Editions and reauthorize (Help->Authorize Computer…).