For your screen, a quick dusting with a clean soft dry cloth will usually do the trick. If your screen is especially dirty, try either a commercial cleaner made for your screen type, or an ammonia free glass cleaner, or isopropyl alcohol mixed with water. Never put the cleaner directly on the screen surface. Instead apply the liquid to a clean soft dry cloth.
For dusting, use a clean soft dry cloth to go over all the surfaces of your computer. Microfiber or electrostatic cloths work well at trapping dust. Pay special attention to the fan vents, and make sure that they aren't blocked by dust. Compressed air can also be a useful tool when cleaning dust from computer surfaces. Do not forget to dust underneath your computer and the cords to your computer which can collect dust.
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