title: WebProxy error: Proxy Authentication Required
body: <p>I use the following code to obtaing html data from the internet:</p>
  
  <pre><code>WebProxy p = new WebProxy("localproxyIP:8080", true);
  p.Credentials = new NetworkCredential("domain\\user", "password");
  WebRequest.DefaultWebProxy = p;
  WebClient client = new WebClient();
  string downloadString = client.DownloadString("http://www.google.com");
  </code></pre>
  
  <p>But the following error is appeared: "Proxy Authentication Required".
  I can't use default proxy because of my code runs from windows service under the special account which there is no default proxy settings for.
  So, I want to specidy all proxy settings in my code.
  Please advice me how to resolve this error.</p>