You can't just "change" what's written. You need to replace your hardware - in this case graphic card, if you want to have nvidia that is. Although you could try to force and load different shaders but in that case it would probably yield all sort of weird results..
Brightness can be changed from in game (Gamma setting) or you can change it with various other settings from console, settings like g_mapOverBrightBits and r_intensity. If your screen is very dark you can try by setting either one or both to two, in that case do a video restart (hold left ALT and press ENTER) after so changes take effect - naturally repeat the process and/or higher the value if needed, until it's set to your liking.