I have a year and a half old Sony Vaio notebook that just developed a problem. It boots up normally but then when you click on any app, the timer spins and spins and the program never comes up. Control-alt-delete doesn't work at that point; the hard drive LED doesn't show any sign of activity. I can, however, open apps if I click on them before the boot up process is completed. But once the boot up is complete nothing works. Any ideas?