I have written a small program displaying sounds and images on the screen when pushing any button. I always start it when one of my little kids crawls onto my lap and start
You'll need a keyboard hook. Unfortunately, this has to be done with P/Invoke; it can't be done with managed code.
Check out Baby Smash! by Scott Hanselman. It's hosted on code plex at http://www.codeplex.com/babysmash Github at https://github.com/shanselman/babysmash
Alternatively, check out ShapeShow on CodeProject, which is similar.
See http://msdn.microsoft.com/en-us/library/system.windows.input.key(v=VS.90).aspx
At the bottom you'll see a simple example, I think what you're looking for is something along these lines:
left windows key: System.Windows.Input.Key.LWin
right windows key: System.Windows.Input.Key.RWin
example:
private void OnKeyDownHandler(object sender, KeyEventArgs e)
{
if (e.Key == Key.LWin) {
textBlock1.Text = "You Entered: " + textBox1.Text;
}
}