Just color it with a permanent black magic marker.... Just kidding. It depends on your laptop since each model is somewhat unique. If yours doesn't have any knobs or buttons then it is software based and you will need to find the program to do it. My E-book has an icon in the lower right as my task-bar for windows vista is on the bottom. The icon looks a bit like the plug to a power cord on top of a battery. This is where I can access settings involving how much power my laptop uses, including how bright or dark my screen should be. I hope this helps you.
