After installing the latest drivers (and rebooting), the desktop of the computer stops responding to any of my actions. It does not display the contents of the desktop except the actual image(wallpaper). It does not respond to pressing the start button. Does not respond to quick start buttons (skype, browsers, any other applications). When you try to press alr+ctrl+delete, gives out a black screen. The 17.1.1 drivers work fine. What could be the problem ?