Depending on what kind of monitor you have, both are relatively easy to clean. One rule that applies to both older CRT monitors, the ones that look like small TVs, and LCDs is to only use a soft, cotton cloth that leaves as little lint as possible. Do not use toilet tissue, paper towels, or anything that’s slightly abrasive. It would be like using sandpaper on a baby’s bottom. You will permanently scratch the surface of your monitor. There are special cleaners that are designed to clean CRTs and LCD monitors, but you should check your manufacturer’s instructions on cleaning before buying any of those products, The one chemical should never be used to clean any type of screen is one that contains ammonia. It’s a great cleaner for cleaning glass, but not for computer monitors. Once your monitor is clean, make sure it’s dry before it’s turned back on. Liquids and electricity are still at war after all these years.