From kJams Wiki
To transfer kJams to another computer there are three steps you will want to do (the order of operations is important!)
- Clone your setup to the new computer
- On the old computer, Deactivate your current installation. To do so, run kJams, then go "Help->Deactivate…". This will free the serial number so it can be used on a different computer. It will also copy your serial number file to the desktop where you can then copy it to the new computer. Note that this file is not needed, because step 1 already copied that file.
- Run kjams on the new computer, it should automatically self-register.