You can improve your Dell D630's battery life and make it more comfortable to look at the screen by adjusting the brightness. Making changes to the laptop screen's brightness is done from the keyboard, using a couple of specific key commands. The entire process takes only a few seconds and does not require any tools.
Press and hold down the "Fn" button at the bottom left corner of the laptop's keyboard to the right of the "Ctrl" key.
Press the "Up" button at the bottom-right corner of the keypad if your screen's too dark. Each press of the "Up" button turns the brightness setting up. So press the button once at a time, then view the changes that result.
Press the "Down" button under the "Up" button at the bottom-left corner of the keypad if your screen's too bright. Pressing the "Down" button turns the brightness setting down. Press it once at a time, then check whether you like the changes.
Release the "Fn" button when you have achieved the desired brightness setting.