While trying to implement a TaskDialog in WPF, I came across a set of code samples for .NET FrameWork 3.0 in Microsoft's website.

The executable that is needed is the one named "CrossTechnologySamples.exe". The VistaBridge project, which is included, contains the necessary library, written in C#, that wraps the required Win32 functions. Apart from the TaskDialog, classes for other dialogs are also provided.