lets encrypt acme certificates in windows IIS

If you want a secure let's encrypt SSL certificate for your windows IIS (internet information services), then there a multiple ways to get it.
See https://letsencrypt.org/docs/client-options/#clients-windows-/-iis

Let’s Encrypt uses the ACME protocol to verify that you control a given domain name and to issue you a certificate. To get a Let’s Encrypt certificate, you’ll need to choose a piece of ACME client software to use.

IIS pre configuration

Run %windir%\system32\inetsrv\InetMgr.exe and add a hostname based http (:80) website first.

Test your hostname website from a different location in the internet (your smartphone or Tor Onion).
win-acme will later detect that hostname based website and offer https alternative.

win-acme

Go to win-acme.com and download zip file.

Alternatively, you can also go to the win-acme git repository and get the latest tagged release there.

Extract the win-acme zip file and then run wacs.exe

IIS post configuration

Run %windir%\system32\inetsrv\InetMgr.exe and remove the hostname based http (:80) website.

Then add the https (:443) hostname based website.

Select SSL certificate.

View SSL certificate and verify let's encrypt certificate issuer, chain and valid from / to dates.

Test your ssl website

Test https connection to website from a different location in the internet (smartphone or Tor Onion).