Before You Begin
In order to enable Vanity URL Options in Active Forums you will need to have access to your web.config file in the root of your DotNetNuke installation directory. It is extremely important that you have a backup copy of this file before making any changes.  At this time, Vanity URLs require IIS 7.

Updates to the web.config file:

1. Open your web.config file using Notepad or another text editor, such as Visual Studio. Do not use Wordpad.
2. Locate the system.webServer section. In DNN 5.1, this will be between lines 50 and 75. In DNN 4.9 it will be at the bottom.
3. Add the following directly below the
   
   <modules runAllManagedModulesForAllRequests="true">
   section:
   
   <add name="ForumsReWriter" type="Active.Modules.Forums.ForumsReWriter, Active.Modules.Forums.40" preCondition="managedHandler"  />
   
   (DNN 4.9 does not have the runAllManagedModulesForAllRequests property.)
   
   
4. Your modules section should now look similar to the image below:
   
   
   
5. Locate the httpModules section and add the following:
   
   <add name="ForumsReWriter" type="Active.Modules.Forums.ForumsReWriter, Active.Modules.Forums.40" />
6. Your httpModules section should now look similar to the image below:
   
   (Make sure that it is the first entry in the list.)
7. Save your web.config file back to the root of your DotNetNuke directory.
8. If you are using IIS 7 with Integrated Pipeline Mode you can now go into the Active Forums control panel and select Enable Friendly URLs from the Main Features section. 

Related Topics:
Getting Started with Active Forums Vanity URLs
Common Questions About Vanity URLs