Digital Editions de-authorisation

After successfully using Digital Editions to download e-books from my library for

over 2 years, it suddenly started to tell me there was an 'activation error'.  After going

round in circles trying to fix this, I decided it might be best to 'de-authorise' myj account

and start again.  It didn't allow de-authorisation, telling me to try again later and, if I

selected 'continue' told me I had entered an incorrect password.
I've tried uninstalling and re-loading to no effect.  I'm not a clever enough computer user to
attempt to follow the Registry fix.  This same problem occurs on both my Windows laptop and desktop.