When I turn my Macbook Pro on it will get to the screen with the apple and a spinning wheel but won't go any farther. For a brief period of time a loading bar appears under the spinning wheel but it disappears before loading at all. I've gone into the recovery mode and verified disk permissions but the repair disk permissions button is not clickable. I tried to re-install Lion over the OS that's already there but the hard drive is locked and I can not figure out how to unlock it. I just finished an important paper that I would like to save so I would like to avoid clearing everything out! If anyone has any advice it'd be greatly appreciate it!