How do I clean a laptop screen and keyboard safely?

What you need

• A soft, lint-free cloth, ideally microfiber. Apple's cleaning guide says to avoid abrasive cloths, towels and paper towels.
• Water, and optionally 70 percent isopropyl alcohol.
• A can of compressed air, with the straw that came with it.
• Cotton swabs for edges and sticky keys.

What to avoid

Apple's guidance is a good baseline for any laptop: no aerosol sprays, no bleach, no abrasives, no hydrogen peroxide, no solvents, and do not spray cleaner directly onto the item. Apple also says not to use a cleaner containing acetone on a screen, and not to wipe excessively, because that can cause damage. HP's laptop cleaning guide gives the same warnings: no harsh chemicals, no abrasive materials, no excessive liquid, and never spray cleaners directly onto the laptop.

Screen coatings differ. Anti-glare and touch coatings can be damaged by strong cleaners, so if you own a laptop with a special display finish, check your manual first. Apple, for example, publishes separate instructions for its nano-texture display.

Step by step: the screen

1. Shut the laptop down and unplug the power adapter. Apple gives these two steps first for MacBooks.
2. Wipe off dust with a dry microfiber cloth. HP starts with a dry cloth and dampens it only for stubborn smudges.
3. Dampen a clean part of the cloth with water only, wring it out so it is barely damp, and wipe the screen gently in light strokes. Apple's instruction for MacBook screens is water only.
4. For fingerprints that will not budge, Apple allows a cloth moistened with a 70 percent isopropyl alcohol solution. Wipe gently and do not let liquid run down to the edges.
5. Let the screen dry completely before you close the lid or turn the laptop on.

Step by step: the keyboard

1. Shut down and unplug the laptop.
2. Blow out loose debris. HP suggests holding the laptop at about a 75 degree angle and using short bursts of compressed air, with the can held upright so no liquid sprays out.
3. Lightly dampen a microfiber cloth with isopropyl alcohol and wipe the keys and the area around them. Apple says a 70 percent isopropyl alcohol wipe, a 75 percent ethyl alcohol wipe or Clorox Disinfecting Wipes may be used gently on hard, nonporous surfaces such as the display and keyboard of its products, while avoiding anything with bleach or hydrogen peroxide. If you use wipes, squeeze them out first.
4. For one sticky key, use a cotton swab lightly dampened with isopropyl alcohol around the edges of the key. Keep the swab from dripping into the keyboard.
5. Dry with a clean cloth and let the keyboard air dry before powering on.

Do not pry keys off unless your manual shows how. Laptop key mechanisms are small and easy to break.

The body, ports and vents

Use a cloth dampened with a mild soap solution, or a laptop cleaning wipe, on the case, palm rest and trackpad, per HP's steps, and dry it with a dry part of the cloth. Apple says not to get moisture in any opening. Short bursts of compressed air can clear the vents; that also helps with heat and noise, which the loud fan thread covers in more detail. HP warns to check the manual before opening a laptop, because opening it can affect the warranty on some models.

How often

HP's guide suggests cleaning the outside every three to six months, more often in dusty places. That is a reasonable schedule for a laptop used daily.

If liquid gets in

If liquid makes its way inside, Apple says to get help from an authorised service provider as soon as possible, and notes that liquid damage is generally not covered by its warranty. Power off immediately. The spill thread has the full sequence.