Here you can find the source of isWindowsLookAndFeel()
public static boolean isWindowsLookAndFeel()
//package com.java2s; //it under the terms of the GNU Affero General Public License as published by import javax.swing.UIManager; public class Main { /**/*from w ww .j a v a 2 s.c o m*/ * @return Is the current Look&Feel Windows Look&Feel? */ public static boolean isWindowsLookAndFeel() { try { final Class<?> clsLaf = Class.forName("com.sun.java.swing.plaf.windows.WindowsLookAndFeel"); // UIManager.getLookAndFeel() instanceof WindowsLookAndFeel ? return clsLaf.isAssignableFrom(UIManager.getLookAndFeel().getClass()); } catch (ClassNotFoundException ex) { return false; } } }