WindowsFontProperty(String key,
    Object backup) 
{
            super(key, backup);
}

 protected Object configureValue(Object value) 
{
            if (value instanceof Font) {
                Font font = (Font)value;
                if ("MS Sans Serif".equals(font.getName())) {
                    int size = font.getSize();
                    // 4950968: Workaround to mimic the way Windows maps the default
                    // font size of 6 pts to the smallest available bitmap font size.
                    // This happens mostly on Win 98/Me & NT.
                    int dpi;
                    try {
                        dpi = Toolkit.getDefaultToolkit().getScreenResolution();
                    } catch (HeadlessException ex) {
                        dpi = 96;
                    }
                    if (Math.round(size * 72F / dpi) <  8) {
                        size = Math.round(8 * dpi / 72F);
                    }
                    Font msFont = new FontUIResource("Microsoft Sans Serif",
                                          font.getStyle(), size);
                    if (msFont.getName() != null &&
                        msFont.getName().equals(msFont.getFamily())) {
                        font = msFont;
                    } else if (size != font.getSize()) {
                        font = new FontUIResource("MS Sans Serif",
                                                  font.getStyle(), size);
                    }
                }
                if (FontUtilities.fontSupportsDefaultEncoding(font)) {
                    if (!(font instanceof UIResource)) {
                        font = new FontUIResource(font);
                    }
                }
                else {
                    font = FontUtilities.getCompositeFontUIResource(font);
                }
                return font;
            }
            return super.configureValue(value);
}

 public  void invalidate(LookAndFeel laf) 
{
            if ("win.defaultGUI.font.height".equals(getKey())) {
                ((WindowsLookAndFeel)laf).style = null;
            }
            super.invalidate(laf);
}