The Register function within the Control Panel will allow you to register/unregister your SI 2017 Server and also allows you check information regarding your registration.
Double-clicking the button above will open the following form:
This displays your SI 2017 Product Key.
This will display your licensing information:
Clicking this will prompt you whether or not unregister your SI 2017 Server:
You can also access your registration information via the Start menu: