I double clicked on the system sounds in the mixer and suddenly I got a beep sound ( one a second ) and it wont stop. I have removed my USB keyboard and mouse and it still keeps beeping. I have tried a system restore and it keeps beeping. I tried an earliar restore point and it keeps beeping. The only thing that works is muting the system sounds. Please help. It is very annoying. the next day: Now the screen on my laptop has stopped working altogether; Its still beeping though.