Tecadmin published a tutorial about redirecting HTTP to HTTPS in IIS on Windows Server.

How to Redirect HTTP to HTTPS in IIS

This tutorial will help you to configure your IIS to redirect any URL from HTTP to HTTPS. This is a good practice to keep production URLs always-on secure page. After completing this tutorial your all the non-secure (HTTP) requests to your websites will be redirected to secure (HTTPS) in IIS on Windows. 

How to Redirect HTTP to HTTPS in IIS