To clean the screen of a laptop computer, power it off, and disconnect the power supply. Use canned compressed air to spray the screen to remove dirt that can scratch the screen.
Use a soft dry cotton cloth to wipe the laptop screen in steady strokes to remove any marks. Spray a clean soft cloth with a 50/50 solution of isopropyl alcohol and distilled water, and wipe the screen from top to bottom gently. Allow the screen to dry and check for any marking. If the screen is still dirty, repeat the cleaning process. Wait until the screen is completely dry before powering on the computer or closing the lid.