You will find all your books in "My Digital Editions" folder
Take backup of the "My Digital Editions" folder in "C:\Users\<USERNAME>\Documents\" (for Windows) or "\Documents\" (for Mac) [on your old machine]
Install ADE on your new machine.
By default "My Digital Editions" folder will be created in "C:\Users\<USERNAME>\Documents\" (for Windows) or "\Documents\" (for Mac)
Transfer all the content of existing "My DIgital Editions" to new "My Digital Editions"
All your books will be added.
Sorry, but I can't follow this at all. I use a Mac.
What does "take backup" mean and how do you do that?
I already have ADE on my new Mac. And it has a Digital Editions folder (which has no editions in it).
How will a new "Digital Editions" folder be created, and where?
The crucial question: *How* does one "transfer the contents" of the old Digital editions folder on the old computer to the Digital Editions folder in the new computer?