I've had my Sony Vaio laptop for 3 years and have never had any problems with it. However, I went to turn it on this morning having used it the night before and everything being fine, and it didn't load up at all. It GOT as far as the Vista loading screen, and then the hard drive made a clicking NOISE and it turned itself off. I tried turning it on again and it did the same thing, but when I did it a third time it booted up fine.

Now I'm really scared that if I turn it off it won't boot up again. I have back-up discs if that does happen but as I've never had to do it before, I don't know how to do it so that I don't lose everything on my hard drive.

Is there any way while it's working that I can find what caused it and if it's likely to die on me again? ThanksI RECOMMEND trying to GET all of your files that you dont want to lose(photos,music etc. ) backed up onto a usb drive or disc.
"clicking noise" may indicate a failing HD. 90% chance it's a failing HDD as suggested above...
Take cruisin's advice ASAP.....the more you use the machine from now til then the less chance you will have of rescuing your data...