^ HelloWorld.java: 4: error: package javafx.stage does not exist import javafx.stage.Stage; ^ HelloWorld.java: 11: error: cannot find symbol public class HelloWorld extends Application ^ ...

If JavaFX application could not launch due to system configuration on your Windows system, then here are a few things you need to do.

Get to know the JavaFX 2 libraries by way of a practical exercise: refactoring a Swing-based text editor into one that leverages the rich UI features of JavaFX (Part 2).