This issue may appear on some (older) versions of Windows:
https://superuser.com/questions/1026496/automatic-services-doesnt-start-automatically-after-windows-restart

In order to fix this issue you’ll need to switch the “HetrixTools Agent” service startup type from “Automatic” to “Automatic (Delayed Start)”.

Here’s the steps you’ll need to follow in order to achieve this.
(this must be done after you’ve installed the HetrixTools Windows Agent)

Start by opening the run command window, type in “services.msc”, and press the “OK” button:

This will open the services window, where you’ll need to locate the “HetrixTools Agent” service. Right click on this service and then click on “Properties”:

A new window will open with the Agent’s properties, where you’ll need to modify the “Startup type” from “Automatic” to “Automatic (Delayed Start)”, and then click the “OK” button on the bottom:

You can now close the services window as well.

And this is it. The agent will now automatically start after server reboots, with a small delay (1-2 minutes) after the server has booted up.