Problem with the FN + F1 in XP

I've made a Dual install with XP for gaming. So here is my problem.
I'm playing Crysis and need to switch FAST between first person and third person view sometimes. And I do that with the F1 key and I'm not able to change it since I'm running the game in DEVMODE to be able to view it in third person.

So how to I make the F keys deafults? So I have to press FN + F1 to decrease brightness and not the other way around.

Oh, and btw.. I'm using the apple wired alu keyboard (danish version).