My HP laptop, which I have had for nine months now, worked perfectly until the other night, when I was listening to music and it suddenly shut down. When I tried to boot it back up, I got an error message, "Non-system disk or disk error, replace and strike any key when ready." I also had options to press some of the "F" keys (F1-F12) to diagnose the problem, BIOS, etc., but nothing is working. I need this laptop fixed and I have gotten nowhere with HP itself. What could this problem be?