Bootcamp w/ WinXP display & brightness problem

Hello. I have a mac book pro and I use it with a view sonic monitor. Before my ultimate problem happened, I was not able to control the brightness of my lap top screen with the hotkeys on the lap top. Even when I changed my display to clone my screen on both of my computer screens the hotkeys for lap top screen brightness wouldn't work. So the ultimate and.current.display problem of mine happened after I cloned both screens than turned my computer off. Now when I turn my computer on all I see is black screens. I have been using my android smart phone to type all of this. Thanks if can help or have Any ideas.