Setting up an SSL certificate for a DotNetNuke Portal
1. To set up the same, you first need to request an SSL certificate for your IIS server.
2. The steps to generate the CSR file can be found at https://support.comodo.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=248&nav=0,96,1,33
3. Once you have your SSL certificate obtained, you can install the same on your server using the steps at https://support.comodo.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=1199&nav=0,96,1,95
4. To set up your DNN portal to use an SSL certificate, login with a host account and go to Admin > Site Settings > Advanced Settings as below:

5. Once you have set the same up, go to the page you want to display using the SSL certificate and go to Settings > Advanced Settings > Other as below:

After you have set up the same for all pages, your website should be displaying the related pages using an SSL certificate.