Are you squinting to see past the dust on your monitor? Does your keyboard hold more food crumbs than the bottom of your toaster? Is the fan on your PC so clogged with dirt that it sounds like a plane taking off? Then maybe it's time to clean your PC -- for the sake of its health as well as yours.

Step 1: Why you need a clean PC
At this very moment, dust bunnies may have your PC in a death grip. Germs are certainly gathering atop your mouse and keyboard, ready to assault your immune system. And your screen... well, chances are it has become smudge central. Even great PCs can be dragged down by performance-choking dirt. Fortunately, with a few helpful products and a little effort, you can easily rescue your desktop from all that grunge.

Step 2: Computer-cleaning supplies
Before you even get started with this project, we recommend that you have the following:

• A can of compressed air
• Wet Ones antibacterial moist towelettes
• Glass cleaner (such as Windex)
• A folded piece of soft cloth or a paper towel
• Lint-free wipes
• A dust mask
• Round IDE cables

Step 3: How to clean a keyboard
Keyboard dirt actually takes two forms. Food crumbs and similar detritus can fall between the keys; leave it alone for too long, and you could wind up with a malfunctioning keyboard. But potentially harmful bacteria can accumulate on the keys themselves, too. Neglecting them may have more serious consequences: making you sick.

To clean out the crumbs, hold your keyboard upside down over a wastebasket and shake it gently. Then hold the keyboard vertically (still over the wastebasket) and use a can of compressed air to spray between the keys. These two actions should dislodge most of the physical grit.

Though plenty of computer-cleaning products are on the market, most are designed to remove only ordinary dust. To obliterate both germs and dirt, antibacterial wipes such as Wet Ones Antibacterial Moist Towelettes should do the trick. Make sure your computer is off, then give the surface of the keys a once-over with the cloth.

Tip: While you're at it, give your mouse a thorough wipe-down -- it can collect plenty of dirt and finger grime, too.

Step 4: Monitor-cleaning tips
A dusty, smudgy monitor may not harbour dangerous bacteria, but it's none too attractive just the same. In fact, a screen seriously caked with grime is unnecessarily hard on your eyes. The fix, unsurprisingly, lies in giving your CRT or LCD a good cleaning, but don't just wipe it with any cleaner you have under the sink. Monitors are delicate equipment and must be cleaned accordingly.

While Windex is suitable for the glass on standard CRTs, never spray it directly on the screen -- the liquid could seep under the edges of the monitor bezel and damage the circuitry within. Instead, lightly squirt some Windex on a folded piece of soft cloth or a paper towel, then use that to wipe the glass.

Another option is some form of lint-free wipes, which promise nonabrasive cleaning. Whichever method you use, your monitor should be turned off (better to see the dust and smudges you're trying to remove), and you shouldn't turn it on again until the screen is dry.

For LCD screens, steer clear of ammonia-based cleaners. Instead, use a soft cloth dampened with plain water. Just make sure the cloth isn't too wet, otherwise droplets could seep under the bezel and cause damage.

Step 5: Clean your computer's fans
Perhaps the most serious dirt-related threat to your PC is dust in the fans. Dust constantly gets sucked inside the case. Over time, it clogs both power-supply and cooling fans. As more and more dust accumulates on the blades and in the motors, the fans have to work harder. If the buildup goes unchecked, the fans may significantly slow down or fail completely. This can lead to serious overheating inside the case, which can cause component failure and, ultimately, data loss.

Once again, you'll need your trusty can of compressed air. Start by powering down your PC, removing the case lid, and locating the various fans. Starting with the power supply, blow through the internal slits from inside the chassis, aiming so dust will exit the back.

Next, blow into the intake fan (if there is one) to push more dust out the back. Finally, blow the blades of the rear exhaust fan clean. If possible, aim just beneath the center, where the motor meets the fan assembly, and blast again. Repeat the process for each fan, keeping the can upright at all times.

Now restart your PC, and while the fans are spinning, spray them once more -- very briefly -- to really send the dust flying.

Tip: Don't forget to run air over the vents on your case lid, too. If they're encrusted with dust, the fans won't be as effective expelling warm air.

Step 6: Computer-cleaning no-nos
While you've got the case open, you'll undoubtedly notice dust in other places -- quite possibly a lot of it. We've seen computer interiors absolutely caked from top to bottom. If yours is, you might be tempted to stick a vacuum-cleaner hose inside and suck out the dust. Don't. Vacuums create static electricity, which is deadly to sensitive electronic components.

On that same note, don't be tempted to reverse the flow of your vacuum and blow the dust out of the computer. The dust inside a household vacuum can be harmful to your health, and you'll be spreading it all over your PC. Also, you risk blowing out sizable particles, which could physically damage internal components, especially if you're using a workshop vacuum. The beauty of compressed air is that it's clean and particle-free.

Before you start blasting, unplug your computer and take it outside -- or at least to your garage. Now, working from the top down, blow out all that dust. (Put on a dust mask, unless you want a face full of grime.) As with the fans, be sure to spray air in short bursts, keeping the can upright and the tube at least a couple of inches from the hardware.

Tip: Check all the cables and plugs inside your PC. Make sure they're fastened securely and that you haven't knocked anything loose during cleaning.

Step 7: Get better airflow in your PC
Dust balls can dramatically impede the airflow inside your PC, raising case temperature to dangerous levels, but a nest of cables can also have the same effect. (They also simply get in the way, making it difficult to quickly replace and install components.)

In most computer enclosures, the prime space-wasting culprits are big, flat IDE ribbon cables. To keep things neat and orderly inside your PC, consider replacing these old-style cables with modern, round ones. Round IDE cables help increase airflow and reduce cable clutter.

With your computer off and its main AC power cord disconnected, simply unplug your current IDE cables and replace them with the new ones. Before replacing the case cover, power up the machine to make sure the cables are connected properly and everything works.

Tip: If you'd rather not splurge on new cables, you can still improve airflow by reorganising the old ones. For instance, fold up any excess cable and fasten it with rubber bands. Just make sure you leave a little slack so that the connectors don't become unseated easily.

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