title: WPF .net 4 application does not work properly on Windows 7
body: <p>I've created a WPF application, C# in Visual Studio 2012 Express for Desktop on Windows 8 with target framework = .Net Framework 4.
  When I run the program in Windows 7, it runs but work not correct. For example: When you click on the button click event is not called. On Windows 7 is installed .Net Framework 4. 
  Nor any error occurs. Simply does not work any button. If you run into Windows 8, then everything works fine.</p>