Question: A friend owns a MacBook (13-inch Late 2007), somehow he's managed to screw up all the function keys.

I've managed to reset the ones for dashboard, expose, etc but the play/pause/fast forward/rewind/increase volume/decrease volume don't work.

Any ideas as to what's happened here and how to fix it?

Answer: 
Go to System Preferences and click Keyboard. There is an option to switch the behavior.

![enter image description here](https://i.stack.imgur.com/LRny7.jpg)
You can use the utility [FunctionFlip](http://kevingessner.com/software/functionflip/) to change the keys from Fn keys to special features. Maybe that can help fix the problem.