Transferring books to another computer

Just copy the files from the old computer to the new one,

using a memory stick, network or any other convenient mechanism.

Then you can open the files with ADE on the new computer.

The new computer must be authenticated with the same account/ID as the old one.

If possible, copy the .epub/.pdf files. 

They will probably be in your user 'Documents/My Digital Editions' directory on the old computer.

You can then open them on the new computer by drag-drop from Explorer or by Open (ctrl-O) in ADE.

If you only have the .acsm files you can only open them by drag-drop or double-click in Explorer.

The new computer will have to re-download the real .epub/.pdf files.

The .acsm files will most likely be in your Downloads directory on the old computer.