From version 3.1 Terra4D installer has the option to run the server as Windows service so it runs without User login.
The service is installed on a separate service user account 'Terra4D', so make sure there is no such user on the system before installation.
When updating Terra4D on such a system, make sure the services 'Terra4D' and 'Terra4Dlogging' are stopped.
Important notes on terra3d-setup:
Configure as service without installation program: