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It doesn't need gas, oil, or new tires. But your computer does need occasional maintenance--it's easy to forget that when you're focusing all your energy on keeping your software and data organized and up-to-date. Without regular maintenance, your PC may flail, sputter, or even grind to a halt, leaving you on the soft shoulder of the information highway.

Dust, grime, and the proverbial waxy yellow buildup aren't just an aesthetic concern; they can lead to serious problems with your PC. The chips and circuits in your system have two mortal enemies: heat and corrosion. Excessive dust and grime can hinder the ventilating airflow through the PC's case and form a layer of insulation on the surface of chips. As a result, chips can overheat and decay prematurely. Likewise, soot and smoke--especially from cigarettes--can, over time, corrode or short out delicate circuits.

The solution is simple: Keep your PC clean. If your system is located in a relatively sterile environment like a hermetically sealed, climate-controlled office, cleaning once a year may suffice. But in dust-prone places (such as rooms with wall-to-wall carpeting or in or near where food is prepared or eaten), performing a basic cleaning every two to three months could add years to the life of your PC.

Any good computer store should carry the following cleaning supplies. An antistatic brush and lint-free wipes and swabs are a must for wiping surfaces. So is canned compressed air for blowing dust out of hard-to-reach spaces. To prevent system damage caused by harmful static charges that can build up on your skin, you'll also need a grounding strap that fits on your wrist. And if your computer is really dirty, a small, handheld vacuum is also worth buying.

You can find cleaning solutions for every component of your PC, but a small bottle of pure isopropyl alcohol is equal to the task of cleansing your motherboard and other cards. If you frequently remove expansion cards and memory modules for cleaning, get yourself a bottle of lubricating contact cleaner.

What to Clean and How

The PC case. First, wipe out excessive dust or other obstructions from the opening for the power supply fan at the back of the case. Do the same for any ventilation openings. Clean the exterior of the case with a lint-free wipe lightly moistened with a very mild soap or ammonia solution. And remember the cardinal rule of cleaning a PC: Always spray the cleaning liquid on the rag, not on the PC.

Motherboard, cards, and memory. Before opening your case, turn off the power. And if your system has any type of active soft-on or sleep mode (check your PC's manual), unplug the system from the electrical outlet. Otherwise, you can leave it plugged in. Put on your grounding strap and clip it to the PC frame if your system can remain plugged into the wall power outlet. If it can't, you'll have to attach it to another suitable ground contact such as a plumbing fixture or other metal object.

Remove excessive dust with a brush and/or canned air. Remember, the object is to remove the dust, not just move it. So turn the case on its side first, or better yet, use a small vacuum cleaner to ensure dust doesn't just resettle.

Over time, expansion cards and memory chips can become partially unseated due to movement and even temperature fluctuations. Cleaning offers a good opportunity to reseat them. Use caution during removal and insertion. Wipe the contacts gently with a lint-free swab and, ideally, a lubricating solution. Cautiously do the same to the inside of each slot on the motherboard. And when you reinstall cards, don't overtighten the screw attaching the card to the case; doing this can partially unseat the card.

The keyboard. Turn the keyboard upside down and blow dust and dirt out from between the keys with canned air. Most keys can be gently pried off to expose the contacts below. Computer shops have special tools for this, but something soft like a pencil with the lead broken off will work nicely. Just be very gentle and apply an even pressure to opposing sides of the key as you lift. Take care not to lose any springs or grommets that may be on the underside of the key. The keys and exterior surfaces--but not the contacts under the keys--can be cleaned with a mild soap or ammonia solution on a lint-free wipe.

The monitor. Thanks to strong electrical fields, monitors are literally dust magnets. Wash your monitor's case with a mild soap solution and a lint-free cloth. Make sure all ventilation openings are dust-free and unobstructed. Monitors produce a lot of heat, so any blockage can cause high-temperature failure. Many monitor screens can be safely cleaned with ammonia-based window cleaners. Check your documentation or ask the manufacturer if your screen has any antiglare or other delicate coatings. If it does, you will have to follow special cleaning instructions.