Just a quick blog this time.
If you want to install different versions of NAV to a same laptop or server, it works just fine. All you have to do is remember to change all the ports to something that has not been used before.
Then, after the install has been sucessfully proceeded, if you use port sharing to simplify some of your management tasks, you have to give following command:
sc config MicrosoftDynamicsNavServer$DynamicsNAV130 depend= NetTcpPortSharing/HTTP
Then you can change the ports back to 7046 and so on, and after restarting the service it will work just fine.
If you have another nav versions installed to standard port ranges, and you fail to set the ports to a new number during the initial installation, DynamicsNAV130 service will not install, and you cannot manually change them, or enable port sharing in order to have working installation.
Funny enough, what happened to NAV120? Perhaps it is the first Business Central version that was never published on premise.
Below are the nav versions and their respective service names: