Here you can find the source of isWindows()
public static boolean isWindows()
//package com.java2s; import javax.swing.UIManager; public class Main { public static boolean isWindows() { Object laf = UIManager.getLookAndFeel(); if (laf.getClass() .getName()//from w w w . j a v a 2 s. c om .equals("com.sun.java.swing.plaf.windows.WindowsLookAndFeel")) { return true; } return false; } }