Running Windows Authentication with IIS Express

You may run into a situation where you have configured your site to run Windows authentication but you get an authentication error when you try to browse it during a debug session.

To fix this issue, you need to edit the Application Host file for IIS and enable Windows authentication. You can find the file here:

\My Documents\IISExpress\config\applicationhost.config

Find the <security> section inside the <system.webServer> node and enable Windows authentication as follows:

<system.webServer>
...<security>
...<authentication><windowsAuthentication enabled="true" /></authentication>
...</security>
...</system.webServer>

And that's all there is to it. :-)