Its not possible. eBooks was allways download in My Digital Edition folder under your Documents. If you move the folder to a other place a new folder was create on the old place.
It appears that you are correct. But see the following paste, that makes the changes correctly. Other products do find that those files have been moved. It is okay that ADE doesn't do that but since I only need to move them myself once in a while I can manage that.
SEE THE FOLLOWING. It is the same for Win 10, my OS.
When the drives are ready, create a folder on D: with your name
Next, open your user folder. In Windows 7, click Start, then click your name in the top of the Start menu's right panel. In Windows 8.1, go to the Search Charm, type
%userprofile%, and select the folder whose name reads something like C:\Users\yourname.
Once there, you can move your documents.
documents, and select that.
When the process is over, repeat it with Pictures, Music, Videos, and any other folders