To add an example .com Redirect to www.example.com , configure web.config As follows:

 <? xml version = "1.0"  encoding = "UTF-8" ?>
 <configuration>
 <system.webServer>
 <rewrite>
 <rules>
 <rule  name = "www"  stopProcessing = "true" >
 <match  url = ".*"  />
 <conditions>
 <add  input = "{HTTP_HOST}"  pattern = "^example\.com$"  />
 </conditions>
 <action  type = "Redirect"  url = " //www.example.com/ {R:0}"  redirectType = "Permanent"  />
 </rule>
 </rules>
 </rewrite>
 </system.webServer>
 </configuration>