There are couple of reasons why a new ID is generated:
1. You check "Generate new ID and send via email" option on step 3 of MSI configuration process. Don't do that if you don't want a new ID generated.
2. You leave "Keep remote Host's INternet ID settings" check box empty on Step 4. You should check that checkbox if you want to keep the ID of the Host you are upgrading.
3. Finally, on the last step when Host settings window appears at the end of the configuration process, do NOT generate the ID in the "Internet ID connection settings". Otherwise, if you do, it'll generate a fixed ID value that will be the same for each installation you use that output installer file for.
3. Didn't get the question. How can you possibly upgrade from Viewer to Host when these are completely different modules with different purpose? Did you mean Agent rather than Viewer?
4. This is what the Agent is supposed to be used for. The remote user can simply download it right onto their desktop and run when the remote session is about to start. The ID and password are then displayed in the Agent window.
As for the Host module, it was intended primary for unattended access when no user intervention is necessary for the remote session to start.
Chris Robertson wrote: I have worked out that the host program will let you know that the computer is started, but the program will not log the computer back in by itself. For Now I will have to get the computer's password and use the auto-logon utility I have.
The Internet ID is generated by the Host itself, not the GMS. The GMS is only an intermediary that uses the IDs supplied by Hosts. The IDs are unique and there is very little chance that on the same ID server, especially if it's a local GMS server, there will be two identical IDs.
Strictly speaking, when you use the Internet ID connection and both computers - Viewer and Host - are on the same network, the program automatically detects "direct availability" of the Host and tries direct connection instead of the Internet ID connection.
However, the pre-requisite for direct connection is that incoming port 5650 on the Host should be open, i.e. allowed in whatever firewall software is installed on the Test PC. It's the default value, you can change the port in the Host settings (Settings for Host -> Options -> Network).