A dongle is not necessary to run REAKTOR 4 and REAKTOR SESSION. You will need the dongle when opening Ensembles written with REAKTOR 3. But once you save these Ensembles with REAKTOR 4 they are readable without the dongle. You also need the dongle when installing the online updatefrom Reaktor 3 to Reaktor 4. However, once Reaktor 4 is installed you will not need the dongle to update Reaktor 4 with any new updates.