{"id":2056,"date":"2025-09-15T19:33:10","date_gmt":"2025-09-15T19:33:10","guid":{"rendered":"https:\/\/certpanel.com\/resources\/?page_id=2056"},"modified":"2025-09-15T19:38:46","modified_gmt":"2025-09-15T19:38:46","slug":"how-to-install-a-wildcard-ssl-certificate-on-windows-server-2025-iis","status":"publish","type":"page","link":"https:\/\/certpanel.com\/resources\/how-to-install-a-wildcard-ssl-certificate-on-windows-server-2025-iis\/","title":{"rendered":"How to Install a Wildcard SSL Certificate on Windows Server 2025 (IIS)"},"content":{"rendered":"\n

Securing your subdomains with a wildcard SSL certificate<\/strong> is one of the most efficient ways to manage multiple sites under the same domain on Windows Server 2025 (IIS)<\/strong>. Whether you want to take full control via manual installation and configuration methods or prefer a hands-off approach using a seamless automated solution (e.g., CertPanel\u2019s AutoInstall Agent<\/a>), this guide walks you through both approaches.<\/p>\n\n\n\n

What Is a Wildcard SSL Certificate?<\/strong><\/h2>\n\n\n\n

A wildcard SSL certificate<\/strong> is a small file that allows you to secure a domain and all of its single-level subdomains. For example, you could secure all first-level subdomains on your domain (e.g., *.example.com<\/em> covers www.example.com<\/em>, blog.example.com<\/em>, mail.example.com<\/em>, etc.) using one certificate.<\/p>\n\n\n\n

This saves time and money compared to purchasing separate certificates for each subdomain individually and simplifies certificate management.<\/p>\n\n\n\n

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Get a Wildcard Certificate<\/a><\/div>\n<\/div>\n\n\n\n

Let\u2019s dive into the two methods you can use to install a wildcard SSL certificate on your Windows Server 2025 IIS.<\/p>\n\n\n\n

Manual Method: Wildcard SSL Installation in IIS (Windows Server 2025)<\/strong><\/h2>\n\n\n\n

Step 1: Generate a Certificate Signing Request (CSR)<\/strong><\/h3>\n\n\n\n

Start by generating a CSR in Windows Server IIS:<\/p>\n\n\n\n

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  1. Open (IIS Manager)<\/strong> (inetmgr).<\/li>\n\n\n\n
  2. Select your server from the left-hand Connections<\/strong> panel.<\/li>\n\n\n\n
  3. Double-click Server Certificates<\/strong> in the center pane.<\/li>\n\n\n\n
  4. In the right pane, click Create Certificate Request<\/strong><\/a> (CSR).<\/li>\n\n\n\n
  5. Fill out the form:
    1. Common Name<\/strong>: Use a wildcard domain by adding an asterisk (*) at the subdomain level you want to secure. For example, *.yourdomain.com<\/em> secures all first-level subdomains.<\/li><\/ol>
      1. Organization<\/strong>: Your company\u2019s official details (i.e., its registered business name).<\/li><\/ol>\n
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        1. Location \/ Country<\/strong>: Based on your registered business address.<\/li>\n<\/ol>\n<\/li>\n\n\n\n
        2. Select Microsoft RSA SChannel Cryptographic Provider<\/strong> with 2048-bit<\/strong> encryption (as a minimum).<\/li>\n\n\n\n
        3. Save the .req<\/em> file (this is your CSR).<\/li>\n<\/ol>\n\n\n\n
          \"The
          Image caption: <\/em><\/strong>Windows Server 2025 IIS Certificate Request window.<\/em><\/figcaption><\/figure>\n\n\n\n\n\n\n\n

          Step 2: Submit the CSR to Your Certificate Provider<\/strong><\/h3>\n\n\n\n

          Once you\u2019ve generated your certificate signing request, the next step is to submit it to the certificate authority (CA) from which you purchased your SSL\/TLS certificate<\/a>.<\/p>\n\n\n\n

          Every CA\u2019s process will look slightly different \u2014 some require you to paste the CSR into a form, while others allow you to upload the .csr<\/em> file directly. Be sure to carefully follow the instructions provided by your CA to avoid delays in issuance.<\/p>\n\n\n\n

          \ud83d\udd39 If you\u2019re using CertPanel:<\/strong>Purchasing your certificate through CertPanel makes this step easier. Instead of dealing with separate upload pages or complex forms, you can submit your CSR through your CertPanel dashboard as part of the guided certificate enrollment process.<\/strong><\/p>\n\n\n\n

          How to Upload Your CSR in CertPanel and Request a Wildcard SSL<\/strong><\/h3>\n\n\n\n
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          1. Go to CertPanel and log in<\/a>.<\/li>\n\n\n\n
          2. Click New Domain<\/strong> (or choose one from your existing list of domains) and hit Continue<\/strong>.<\/li>\n\n\n\n
          3. On the next screen, choose Manual Installation<\/strong> and hit Continue<\/strong>.<\/li>\n\n\n\n
          4. Here, you\u2019ll be able to paste your CSR data.<\/li>\n<\/ol>\n\n\n\n
            \"A
            Image caption<\/strong>: A demonstration of where to paste the CSR details in CertPanel.<\/em><\/figcaption><\/figure>\n\n\n\n\n\n\n\n

            In the next few steps, you\u2019ll: <\/p>\n\n\n\n