Bad Device Key or PKCS12

[JeannetteO]

I borrowed a book from the library when I tried to download to my computer I get a bad device key error message.  It is a book I'd requested so would like to get it read so others can read it. I have been able to download and sideload on to my e-reader previously  with no issues.  I just downloaded Windows 10 and that seems to be when the problem started. I deleted adobe digital editions and reinstalled to be sure to have the latest version and that didn't work either. 

Any one have a fix?

[JeannetteO]

I finally found two answers. I had to try both but it worked.

I was advised that if you open Adobe Digital Editions and then press “Ctrl + Shift key and the d key” at the same time a pop up box will appear “ Erase computer authorization” if you click the button on the right “ Erase Authorizsation”.

Then the first time you use Adobe Digital Editions, you will be asked to authorize the software with your ID. Should you not receive this prompt, click ‘Help’ and ‘Authorize this Computer’

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.  Close ADE and reopen.

Now Authorize ADE again.