I have been having a problem where when my computer goes to sleep then I wake it. Everything is invisible execpt for my background. I can ctrl+alt+delete and the screen will go black. I can use the arrows and enter to selete the options on that screen. When I hit enter on the switch users option I hear the sound of it signing out then logging back in. But now, it is like that even when I start the computer. It startd all fine and stuff, but everything is invisible. I can hear all of my programs that run on start up ( like skype signing in). I am running Windows 7. Please help. My computer is my life.