Moved to Digital Edition forums
You probably didn't need to restore the reader, but it won't matter.
I think almost certainly that the error message is misleading (like most ADE error messages).
Try removing the 'authorization without ID' from ADE on the computer.
Hit ctrl-shift-D while in Library view on ADE. (cmd-shift-D if on a Mac).
Restart ADE, and then try again to register with your original Adobe-ID.
No promises, but I think there is a good chance that will work.
You can then plug in the eReader, which you will almost certainly need to reauthorize with the old ID.
After that, everything should work fine; fingers crossed.
Thanks for your help, everything is working fine. I'm really happy now!