Securing your website is essential to protect user data and build trust. Let's Encrypt offers free SSL/TLS certificates that enable HTTPS on your IIS web server. This guide walks you through the process of setting up Let's Encrypt on IIS for secure hosting.

Prerequisites

  • An IIS web server installed and running.
  • Administrative access to the server.
  • Domain name pointing to your server's IP address.
  • Basic knowledge of Windows Server and IIS management.

Installing the Win-ACME Client

Win-ACME (formerly known as Let's Encrypt Simple Windows/Certify The Web) is a popular tool to obtain and install Let's Encrypt certificates on IIS. Follow these steps to install it:

  • Download the latest version of Win-ACME from its official website.
  • Extract the ZIP file to a folder on your server.
  • Run the wacs.exe file as an administrator.

Requesting and Installing a Certificate

Once Win-ACME is running, follow these steps to generate and install your SSL certificate:

  • Select Create new certificate.
  • Choose Single binding of an IIS site.
  • Select the domain names for which you want the certificate.
  • Follow the prompts to validate domain ownership via HTTP challenge.
  • Allow Win-ACME to automatically install the certificate in IIS.

Configuring IIS for HTTPS

After the certificate is installed, configure IIS to use HTTPS:

  • Open IIS Manager.
  • Navigate to your website.
  • In the Actions panel, click Bindings.
  • Add a new binding with Type: https.
  • Select the newly installed SSL certificate.
  • Click OK to save.

Automating Certificate Renewal

Let's Encrypt certificates are valid for 90 days. Win-ACME can automate renewal:

  • During initial setup, choose the option to schedule automatic renewal.
  • Ensure the Windows Task Scheduler runs the renewal script periodically.
  • Verify renewal by checking the certificate details in IIS after renewal.

Conclusion

Using Let's Encrypt with IIS is a cost-effective way to secure your website with HTTPS. By following these steps, you can easily obtain, install, and maintain SSL certificates, ensuring your site is trusted and secure for your visitors.