Windows XP supports look and feel customization using 'themes'. Themes are collections of settings and images that provide a complete appearance 'package' for your XP system.

When you select a new theme, Windows XP takes on a customized appearance that is controlled by the theme's settings and imagery. The customizations can include fonts, colors, desktop wallpaper, and other Windows XP visual styles elements. You can give your Windows XP system a completely unique look and feel.

Of course, you can override the theme's settings, so, if you want to use a different wallpaper/desktop background, or change the font size or title bar color, you can change those settings.read more »