Trying to install the server part of a network (concurrent) installation gives an error indicated I have already install and registered on a different server.  How is this solved? 

Cause: Typically the license service can only be installed on one license server and the TIBCO registration server indicates this has already been installed.  If a server install is attempted again on another server,  registration will fail  and the error "maximum number of installs has been reached" will appear.  

1.  Uninstall Statistica from its current server location.

2.  During the uninstall process, a message dialog will pop up asking if the registration server should be notified about this un-installation.  Please select Yes. 

3.  A message will indicate if the registration server was successfully contacted or not.  If successful, then the registered install has been marked as Uninstalled.  If unsuccessful, then please create a TIBCO support case with the server hostname and Statistica serial number.  Create the support case here:  https://support.tibco.com/s/

Related knowledge base articles:
Concurrent Network License (CNET) installation steps
Error: "You have reached the maximum number of installs allowed" when installing a stand-alone version of Statistica