It doesn't matter if you're a Mac or a PC, a business executive on a sleek laptop or an uber gamer on a custom desktop, the fact of the matter is: your computer is grimy. That's right — the mouse and keyboard that you spend all day touching? Both collect germs quickly, and your shag carpet and shedding cat are doing no favors to your computers fans.
Just like hall closets and kitchen cabinets, computers need a good cleaning at least every six months or so. Fortunately, it's not a complicated process, but you will need soft, lint-free cloths, some compressed air, distilled water, white vinegar, and cotton swabs or a soft brush like the OneClean KeyBoard Cleaner. The majority of the work here can be done by gentle household items; you'll want to stay away from a lot of the chemicals found in common cleaners (no ammonia, ammonia-based, ethyl alcohol, acetone, ethyl acid, or methyl chloride).
First things first: your computer should be completely powered down and everything (mouse, keyboard, monitor, power cord) should be unplugged. If you have a laptop, remove the battery.
Desktop: Wipe down the tower with a lightly dampened cloth, and follow with a dry cloth. Remove dust and debris from fans, input ports, air intake and exhaust areas of the computer with compressed air or a soft brush. Use a pencil to hold fan blades in place while cleaning. Open the CD drive and carefully blow air in and around the tray to remove dust. Run the dampened cloth over cables and power cords (again, these should be disconnected), following with the dry cloth, and secure with a cord keeper like the CableClip.
If you're comfortable unscrewing your tower and poking about inside, then go forth with caution — you'll first want to make sure that your tower is on a table and safe from any static charges, then continue carefully blowing and/or brushing out dust from the fans and internal components. If you're using compressed air, don't turn the can upside down, and be sure to keep it about two inches away from the components.
Laptop: For a laptop, the process is more or less similar; the difference here being that the inside of the computer might be more difficult to access. Many laptops have keyboards that lift up to expose the innards, but you're probably safe just wiping down the outside and blowing dust out of all the crevices. A putty knife or guitar pick can be used to pry open seams.
Monitors: If you're still working off an old-school CRT monitor, you're permitted to use glass cleaner (as these types of monitors are made with glass), but if you've got any of the newer, slimmer displays (LCD, Plasma, or any variation thereof), you'll need to use a gentler method.
First, unplug everything and give the monitor time to cool. Then run your soft cloth over the screen to wipe away dust, and use your compressed air (or brush) to clean crevices, grooves, fans, and outputs. If a dry cloth doesn't remove all the grime, don't press harder, just move to the next step. If your monitor's manufacturer recommends a screen cleaner spray, you can use that — spraying it on the cloth first, never spraying on the display — otherwise use something designed for LCD screens like Klear Screen. Wipe down the frame and any related cables with the dampened cloth, followed by the dry cloth.
Keyboard: Unplug, then turn over an empty trash can and shake and tap to remove debris. Next, working with a brush or compressed air, remove dust and debris from the keys. You may need to alternate these tasks. Add more fun by using Cyber Clean putty cleaner.
If you're looking for a thorough clean, use a chop stick and cloth, or a cotton swab, and some isopropyl alcohol to gently clean under and around each key — keeping in mind keys can be easily popped off and on. Some keyboards can even be cleaned in the dishwasher, but you'll obviously want to check with the manufacturer first. Wipe down the frame of the keyboard and and cords with the dampened cloth, followed by the dry cloth. If you find yourself eating at your desk frequently, consider a keyboard cover like the iSkin or Moshi ClearGuard.
Mouse: Unplug your mouse, then wipe down the outside with the damp cleaning cloth and some isopropyl alcohol. (If you're worried about damaging any of the plastic parts, dilute with one half parts water). Dampen a cotton swab and work around the LED sensor. If you've still got a mouse with a trackball, pop it out and clean out the housing before replacing it. Roll any trackballs and make sure all the buttons are clicking and not sticking, then wipe down the cord and dry.