Repair a Scratched or Finger Printed Monitor Screen

Here is a simple way to fix a smudged or scratched monitor. It is necessary to have a clean display surface before attempting scratch repair.

Steps

Take a soft cloth and wet a corner. (Do not use tap water, as it can leave a deposit or streaks from the mineral content - use Deionized water instead!)
Gently wipe the screen in circular motions while the computer or TV is off.
Wipe it in up and down direction across the screen.
Use the dry side of the cloth to dry it in circular motions.
Repeat if necessary.

Windex, Brasso, or any other solution which contains ammonia, or any other solvent including acetone, will damage ARAG (anti reflective , anti glare) coatings or films.
Never use abrasive solutions or solutions containing solvents on screens with ARAG coating/film.
Few CD/DVD repair fluids can be used to fill or smooth over small scratches or scrapes in the plastic-like first layer of anti glare films. This is because some fluids contain solvents and/or abrasives.
You can also use Pledge or some similar wood polish: It will fill in the scratches on computer monitors or CD's. However, it will leave discoloring blemishes, often more objectionable than a scratch. Petroleum jelly has the same effect, and is much harder to remove. Plastic model glue has irreversible negative effects.
Damaged ARAG films can be peeled off, and new ones applied. Operating without an ARAG film will reduce contrast, alter gamma, and therefore distort picture of display unless adjusted to compensate.

If applicable,peel off, or scrub away, ARAG film. This is irreversible, make sure you can buy replacement ARAG film.
Proceed with usual abrasive techniques (buffing). Glass repair resins may be more effective for very deep scratches.
If applicable, apply new ARAG film. Make sure the new film is similar in properties to the original. Be sure to check your gray scale tracking and adjust the display as necessary to avoid color and luminance distortion due to varied transmittance of new coating.

If you are performing this on a laptop, tip the screen back as far as it will go so water doesn't get on the keyboard.
The best cloths to use are the soft golden colored ones with the zigzag edges.
To determine whether your display has ARAG coating, check for purple colored reflections from the glass. Most anti reflective coatings reflect the high and low end of the visible light spectrum, reducing mainly the reflected light from the middle of the spectrum. Beware some displays have an anti static coating which can not be identified with this method.