I have done some searching and asked around, but haven't made much progress. I want to override the original functionality of the Function keys. I have tried keyboard hooks, but they don't seem to be working for me. Are there any pointers?

Have you tried

if(e.keycode == keys.F2)
{
//Insert Code here
}

Yes, the problem with that being, it doesnt consume the key press so Windows doesn't see it.

Wait what are you trying to achieve in this program?

Turn a non media keyboard into a media keyboard... I broke my dinovo edge and I AM NOT buying a new one.

So you want to be able to Pause, Rewind,+ Volume, - Volume?

Globally overriding keys is no doubt possible but for this specific purpose AutoHotKey is probably more well suited.

It's basically a scripting language for keyboard macros, making the F1-12 keys send media buttons instead can be done in a few lines like this script I use on my laptop to emulate the context menu key:

Here pressing the right control and right alt sends the "AppsKey" (context menu).