Hi Traffic! Thank you for your answer!
This is what I did:
1) Uninstalled the previous OpenVPNService with this command "SC DELETE OpenVPNService"
2) Typed and run "nssm install OpenVPNService"
3) Edited only the first tab (the others I left them as default):
4) Rebooted the PC
Now the service is showed as
Paused. Certainly something is missing. For example, the "dependencies" tab is empty (and I don't think it's supposed to be).
Any help is welcome!
Thank you!