It started when I tried to install my scanner, a Vissioneer 7600. Everytime I tried to use a CD or DVD it locked up. ctrl alt delete won't work, had to push power to shut off and restart. I went to add/remove programs to take off the scanner and couldn't find it. Now it won't boot at all, just sings this high pitched continous sound. Also, when it was working, I couldn't get anywhere online. All I get is "page cannot be displayed".