lately I asked the forum how to set up “cronjob” under Windows which allows for running letsencrypt.exe automatically. So the answer was to use "“scheduled task” which is exactly true.
You need to run as an admin - start, enter cmd.exe in the Search box, then right click > choose the option run as administrator. Don’t forget to restart after the changes have been made. My web server was previously on Ubuntu 16.04 so there were two basic modes to run (I used Standalone).