I've just spent 2 hours in live chat with Adobe. If you have this problem they say there's is nothing that can be done. He suggested deleting the software as it will never work for you and to use OverDrive instead.
Unfortunately, With out the password it is not possible to de-authorize.
So that means I can't use your product and I can't borrow or buy ebooks?
I guess I have to use OverDrive then?
You can try that.
Well I guess thanks for telling me Adobe is of no use to me and sending me to your competitor.