The English interface is set by default on Windows server 2016.
To install the Russian-language interface, the first step is to connect to the server via RDP.
After loading the system, go to the control panel Start → Control Panel.
Next, let's go to the language settings.
To do this let's open the section Clock, Language and Region and click Add language.
The Russian language will appear in the settings, with the status Available for download. This means that it has been added, but not yet downloaded. Press the Options button.
In the new window, click Download and install language pack.
Then we have to wait for the language pack to finish downloading and installing.
Next, set the default language, click Move up and preboot the system.
Important: the connection to the server will be broken and all open programs will be closed.
After restarting, you will see Russian-language Windows interface.