RealVNC
From Hostek.com Wiki
How to configure RealVNC Server on Windows VPS
Once you have download and installed RealVNC you will need to make sure that you have an exception in your windows firewall to allow connections to your Public IP.
- Open Windows Firewall and add an inbound rule
- Click on Port and define the port you want allow (default is port 5900)
- make sure you allow TCP and choose Allow Connections
- add an outbound rule and repeat steps 2 and 3
Configure VNC Usermode and Server Mode
While the VNC Server in Service Mode icon does not appear in the Desktop Tray in an RDP session, it will most likely be running in the background. Could you do the following:
- Start VNC Server in Service Mode.
- Open VNC Server in User Mode, make note of the IP Address (you will need
this to connect to the VNC Server in Service Mode)
- Close VNC Server in User Mode, then exit out of the RDP session.
- Enter the IP Address that was shown on the VNC Server in User Mode into
the VNC Viewer application (please note, the Public IP of your User Mode Server) in order to connect to the Service Mode Server, you will need to connect to Public IP You should now be prompted for a password and username upon connecting via VNC Viewer, by default these details are those of the Windows System User who launched VNC Server. When you connect you will be prompted with the local login screen.
From here you should be able to login and see VNC Server in Service Mode in the Desktop Tray, and be able to configure it in the same way you were able to configure VNC Sever in User Mode.