HELP! Why is this disabled?

on my detail settings, i have a major problem, i've been thinking there's been something wrong with my graphics and then i realized it was the light that was off
i go to turn it on, but it's disabled, and uneditable... does anyone know why? it's pretty weird..

I got this problem also, I believe its in the video card of the computer, not a problem of the game, because when I went to an internet cafe and played live 08, this problem also occurs, and then I tried to know what video card the computer has and it only has 96mb, but when I played the game in my pc at home, it has lighting settings on-off, is ur video card small?? if not maybe I was wrong

Your videocard is unsupported by the game, that is why lighting is grayed out.

oh.. so there's no way to enable it?

Unfortunately not.