Nail boards back on window
Then, after some intensive thought, you realize that it was the opportunity you were waiting for to be able to get inside the castle. Taking out your crowbar (Which you also conveniantly brought) you pry the boards away from the window until you can see the dust choked darkness inside
Seeing that the boards are about to fall off you take out your nails, and a hammer (Which you conveniantly brought) and nail the boards more securely on the windows.
