My HP Pavillion won't start!!!! Please help!!!!

Hello,

I've had my HP for about 4 years and its always worked great. Last month I put a music CD on to download the content, and it frozed. Then when I tried to restart it, it got to the black screen right before opening Windows, with the loading bar, but stayed there. Its been doing that ever since.

I've tried the safe mode, and last succesfull start, but it goes back the black screen and stays loading for ever.

My great concern is that I might loose all my school content in it.
If anyone can give me an idea it would be greatly appreaciated.

Thanksss!!!