ANSWER FOR- My Dell XPS Studio Laptop Keyboard Wont Light!?

Easy Fix! Go to the "FN" key on the bottom of your laptop closest to you (this is ONE key, NOT F & N!), then go to the lower right key that has an arrow pointing right on it (also has a dimmer ensignia above it), press the FN key, at the same time press the right arrow key to adjust between three settings, "On", "Half-Brightness", "Full Brightness". Your keyboard in now LIT!!