title: What's different about Screensaver preview in Windows 8?
body: <p>I'm working on a simple WPF based screensaver and can't get the thumbnail preview to work. </p>
  
  <p>When you open the display control panel and go to configure the screensaver, the selected screensaver is supposed to display a thumbnail preview within the dialog:</p>
  
  <p><img src="https://i.stack.imgur.com/2J8CS.png" alt="Display Properties - Screensaver"></p>
  
  <p>I've found a number of good examples online of how to do this, including:</p>
  
  <ul>
  <li><a href="http://stuff.seans.com/2008/09/01/writing-a-screen-saver-in-wpf/">Writing a screen saver in WPF</a></li>
  <li><a href="http://wpfscreensaver.codeplex.com/">WPF Screensaver (Codeplex)</a></li>
  <li><a href="http://cchearts.codeplex.com/">CC Hearts Screen Saver</a></li>
  </ul>
  
  <p>Following these examples, I couldn't get anything to work - the preview thumbnail turns black, but nothing else appears. Downloading each of these (and a few others) and running them had the same result - a blank preview thumbnail. I've done this before on Windows 7 and it wasn't hard, so I was a bit frustrated.</p>
  
  <p>Copying the binaries across to a Windows XP machine, I found that each of them showed a preview thumbnail successfully. </p>
  
  <p>So, there's clearly something that's changed between Windows 7 and Windows 8.</p>
  
  <p><strong>What do I need to do differently to enable my WPF screensaver to properly display a thumbnail preview on Windows 8?</strong></p>