I'm sorry - I just tried it again and it said "error - check activation" Again, I'm guessing I'll need to de-authorize but am afraid of losing all books. Appreciate the help from anyone.
You need to rebuild the activation file but first you need to delete it manually first.
You need to delete out a few registry keys to clear the activation for ADE. You must have administration authority.
On Windows it can be found here:
Open Windows Registry by using the command prompt and typing 'regedit' or by opening the start menu and searching for 'regedit'.
Search for the following folder:
The 'Activation' folder can be entirely deleted.
On Mac it can be found here:
In Finder, find the 'Go' option on the menu bar and click 'Go to folder' and type the following in:
~/Library/Application Support/Adobe/Digital Editions/
Delete the activation.dat file within the 'Digital Editions' folder.
Restart ADE and it should be deactivated at this point. You should be good to sign back in. So long as you sign in with the original ID that was used for the books, you'll still be able to read them.
Thank you! It worked!