title: MVC windows authentication grayed (greyed) out in project properties
body: <p>I am trying to use Windows Authentication in a VS 2013, MVC 4 project that was originally done in VS2011.</p>
  
  <p>It worked fine on VS2011, but when I moved to VS2013 on the same machine, using IIS 7 problems ensued.</p>
  
  <p>I have windows authentication set in web.config (and anonymous authentication disabled):</p>
  
  <pre><code>&lt;security&gt;
    &lt;authentication&gt;
      &lt;anonymousAuthentication enabled="false"/&gt;
      &lt;windowsAuthentication enabled="true"/&gt;
    &lt;/authentication&gt;
  &lt;/security&gt;
  </code></pre>
  
  <p>However, these attributes are grayed (greyed) out in the <strong>"f4"</strong> properties window for the VS2013 solution.</p>
  
  <p>When I debug the program, I get the following error:</p>
  
  <blockquote>
    <p>HTTP Error 500.19 - Internal Server Error with Error Code 0x80070021</p>
  </blockquote>
  
  <p>I have tried editing C:\Windows\System32\inetsrv\config applicationHost.config per similar posts in forums, and restarting the services, but the problem still persists.</p>
  
  <p>Does anyone know how to please solve this?</p>
  
  <p>Thanks in advance.</p>