title: Web Api hosted in IIS - 401 Unauthorized error
body: <p>I wrote Web Api, for intranet environment. Like as other applications, Web Api configured for Windows Authentication. But the error returned is:</p>
  
  <pre><code>HTTP/1.1 401 Unauthorized
  Cache-Control: private
  Content-Type: text/html; charset=utf-8
  Server: Microsoft-IIS/8.0
  WWW-Authenticate: NTLM
  WWW-Authenticate: Negotiate
  X-Powered-By: ASP.NET
  Access-Control-Allow-Origin: *
  Access-Control-Allow-Headers: Content-Type
  Access-Control-Allow-Methods: GET, POST, PUT, DELETE, OPTIONS
  Date: Thu, 13 Mar 2014 22:05:12 GMT
  Content-Length: 6171
  Proxy-Support: Session-Based-Authentication
  </code></pre>
  
  <p>how can I fixed this?</p>