title: How is Windows checking its users are online?
body: <p>I'm using the <code>ActiveDirectory</code> library in c# to pull user and group details etc.</p>
  
  <pre><code>using System.DirectoryServices;
  using System.DirectoryServices.ActiveDirectory;
  using System.DirectoryServices.AccountManagement;
  </code></pre>
  
  <p>I googled how to find if a user is online but apparently there's no way to do this using ActiveDirectory so I'm left wondering, how is Windows seeing who's online? e.g. on Outlook, SharePoint or Skype, we see a user's status (red, green, yellow - busy, available, away etc.)</p>
  
  <p>Is there a way to do this building on any info I can get from ActiveDirectory?</p>