Adobe Digital Editions – Anonymous Activation
If you do not have an Adobe id, and want to get right to reading the book, you can choose to authorize your device without an ID. You can continue to download and read all books in this utopian environment, as long as you don’t need to transfer these books to a different device, or you de-authorize ADE.
Now if you wish to do one of the above, and still preserve access to the books you’ve currently downloaded, follow the steps below:

So this gives rise to the question: If I have activated ADE without an ID, is there a way to activate with an Adobe ID and continue reading books fulfilled using the anonymous account, and also move the books to other devices? The answer is YES, but there is a catch.
You can achieve it and activate ADE again directly without de-authorizing the existing anonymous account. The catch here is, it should be a fresh Adobe ID which is not activated on any other device or computer.

"I have an Adobe ID and am using it on another machine. Is it possible to associate the existing ID with the anonymous account?”
No, because once an ID is activated, a unique UUID will get associated with this user account. In the fresh ID case, it will be associated with the UUID of the Anonymous account.
“Do I have to maintain both the accounts?”
You can join your existing account with the newly created account, which will allow devices activated with one Adobe ID (or Vendor ID) to read books previously fulfilled with another Adobe ID (or Vendor ID).
"I have de-authorized anonymous activation without activating it with new Adobe ID and lost access to my books fulfilled on my PC with anonymous activation". Can I access the books again?"
No, you must get a new acsm file from the vendor and fulfill again.

