Macbook Will Not Load

I have owned my Macbook for a couple of years. I have never had any problems with it until recently. What I noticed first was that my audio buttons (on the keyboard itself) did not work, nor did the brightness buttons. I also tried loading certain programs but they would not cooperate. They would begin to load and then suddenly quit. Thinking that all my Macbook needed was a restart, that's what I did. When I tried turning it back on, my Macbook would start. I would hear the Mac sound. And then it would go to the load screen. It does not go beyond this point, even after hours of letting it sit.

I even tried taking off the battery and putting it back in, but that did not have any effect.

I am out of ideas on how to get my Macbook to work.