title: Issue using Show Desktop with SetParent in WPF
body: <p>I am working on a simple active desktop replacement for a school that is migrating to Windows 7. The idea is to create a window with a few large buttons with pictures on so that young children who have trouble reading can use them. </p>
  
  <p>I am using SetParent() to set my window's parent to 'Progman' so that it is always at the back and is not minimised when a user chooses to 'Show Desktop'. Everything works fine on Windows XP but on Windows 7 when users click 'Show Desktop' the window remains but the contents are replaced with the users Windows background. The buttons still work (you just can't see them) and if you resize or otherwise update the window they appear again. A picture of the problem:<br> <img src="https://i.stack.imgur.com/3drSw.jpg" alt="https://files.me.com/adt100/ggi99t"></p>
  
  <p>Any ideas why this is happening? Does anyone know a way I could force a refresh of the window when 'Show Desktop' is pressed?</p>