On our Dell Vestro 200 desktop we have Windows XP. We can not get our Wallpaper to show. We right click on screen and properties, desktop, select a picture which appears on tab, when clicking on apply, nothing happens. When we use Windows Explorer and bring up a picture (jpeg) and set it as Wallpaper again nothing happens. Our screen is blank, except for icons. Also when selecting a screen saver, it will revert to a generic. Any advice? Did a virus & rootkit scan. There where some, now none.