DefaultMutableTreeNode gn = new DefaultMutableTreeNode(g.getName());
				gn.setUserObject(g);



        	DefaultMutableTreeNode w = (DefaultMutableTreeNode) value;
        	WiiGame ww = (WiiGame) w.getUserObject();

This errors Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: java.lang.String cannot be cast to com.Friendcodes.wiiSave.WiiGame