How to clean your PC of dust and dirt

A dirty PC could crash at any time. Clean it before disaster strikes

How to clean your PC of dust and dirt

Tips for improving computer performance usually concentrate on streamlining and maintaining operating systems, boosting speed with new RAM, upgrading video and so on. However, you can give your machine a speed and reliability upgrade easily with the help of a vacuum cleaner and a soft brush.

A build-up of dust on vents, components and fans ruins your machine's ability to keep its cool, and when a computer runs at a high temperature, it goes more slowly.

In the worst-case scenario, your cards, power supply units and motherboards can fail entirely. On a more basic level, dirt and dust can gum up moving parts and affect performance.

Here, we'll show you how to physically clean your PC, keyboard and monitor. As a bonus, we'll also tell you how to keep your computer grime-free once you've fettled it. You'll add years to the life of your hardware and improve its performance.

Before you begin, remember that PC cleaning is a serious job that - depending on how far you want to take it - will require some technical skills. As a gauge, if you're comfortable with fitting new memory or upgrading a video card in your PC, you should be able to complete all the steps.

Gear up, power down

Start by assembling your tools. You'll need a small, soft brush - the kind you might use for painting a window or door frame. Make-up brushes are also ideal. Go for the best quality you can afford, because economy ones often tend to shed hairs.

A can of compressed air, which should be available from most computer retailers and hardware shops, is also required. Make sure you have soft, general cleaning cloths for the exterior of your machine and the computer's cabling.


The final essential tool is a full-sized vacuum cleaner with a nozzle attachment, or a fully charged handheld device. Some other tools may be handy, but aren't necessities. For example, an anti-static wristband will prove useful once you've opened up the computer.

You might also want to use a switch cleaner, which is a spray solvent that eats dust and can be used on ports and contacts. These aids can be bought cheaply from Maplin or larger computer retailers.

Switch off your computer and unplug it from the mains. If you've been using it, you should leave it to stand for at least 30 minutes before you begin the cleaning routine. This will give internal components a chance to cool down, and also reduce the risk of electric shock from any stored charge that may potentially injure you or damage your computer.

Carefully unplug all your peripherals and input devices, then set the cables to one side, because you'll be giving them special attention.

Place your computer on a raised surface - an empty table or desk will do fine. Attempting to spring clean with the computer on the floor or in another awkward place will just make things more difficult. You're now ready to begin.

step 1

Start with the easy part - cleaning the computer's exterior. Using a vacuum cleaner hose or handheld vac, remove dust from vents and any visible USB, video and networking ports. Dust can get into infrequently used ports, increasing the risk of malfunction.

Be careful when working near fans, because causing them to spin in the wrong direction can damage their operation.

When the excess dust has been removed, carefully wipe down the exterior of the case. If there's any sticky grime on there you can use a very damp cloth or a little household surface cleaner to get rid of it. Take care not to go near any ports or vents with liquid.

It's now time to open up your machine and begin the serious bit of the exercise. With most modern computers, you should be able to remove the side panel using a catch, but on older machines you may have to undo a couple of screws first. Your aim is to get inside the case so you can see the damage caused by months of dirt.

Inside and out

You've now reached your first decision point. If you're happy with the technical aspects of computer maintenance, proceed with caution. If you're less confident, we suggest skipping over this bit and simply vacuuming the interior.

step 2

If you're feeling brave, put on your anti-static wristband. If you don't have one, touch something metal like a radiator to discharge any static that's built up before you begin.

To clean inside the case and around the motherboard as effectively as possible, it's best to remove any add-on cards. These can include ones for video and audio, networks and port extensions. You can also take out memory chips carefully, but only if you're happy about doing so.

Place the removed components on a clean and clear surface. If you're a completist who's keen to have a spotless PC, you can also remove any internal connector cables. It's best to leave power supply cables - the yellow, red and black leads feeding into drives and other components - in place. IDE ribbon cables, SATA cables and audio connectors can be unplugged and set aside.

Dust buster

You may be amazed at the amount of dust that can accumulate inside a PC case. It's not unusual to find spiders' webs alongside the balls of fluff and general detritus. With the case open and exposed, you can vacuum most of what's built up straight out using the hose from your cleaner.

Be careful when you get near fans, and avoid nudging or touching your PC's components with the nozzle.

When you've removed all the dust that's easy to vacuum out, it's time to turn to the brush and can of compressed air. Starting from the top of the case, use the brush to gently swish any dust off the motherboard and slots.

step 5

Compressed air can then be used to dislodge more stubborn grime, but make sure you only use it in very short bursts and follow up with a sweep of the brush, moving the dust out of the case. These short attacks are highly important, because anything longer can introduce moisture to your system, possibly causing a short circuit.

Now wipe down the bare areas of the case with a clean, dry cloth, being careful to avoid electrical parts. Always use the brush for this - you risk leaving behind conductive material otherwise.

If there are any particularly stubborn areas of grime - more likely if you're a smoker - you have another choice. If the dirt is on the case interior, you can use a small amount of surgical spirit on a lint-free cloth to wipe at these spots carefully. If the ground-in dirt is on electrical components, though, you may do more harm than good trying to remove it. You'll just have to live with it.

Side project

As an advanced user, you may want to finish your spring clean with a bit of light repair, especially if you've noticed a noisy fan or two in your system recently. Case fans are usually closed systems, with internal lubrication that should last a lifetime. Occasionally, dirt can compromise that system, soaking up lubricating oil or enabling it to dry up. The result can be a noisier, hotter computer.


In this case, you can try a drop of sewing machine oil in the centre of the fan. You'll find the stuff on Amazon for about £3 a bottle. You'll need to remove the fan from the case before applying lubricant, but that's not a difficult job.

Carefully detach the power cable from the motherboard first, then remove a screw from each corner of the fan. Pull the fan free of the case. In the centre of the fan, there should be a sticker. Peel that back carefully and put it somewhere safe.

You should see a rubber or plastic plug underneath the sticker. Remove this and add one drop of oil to the spindle. That's all you should need to get things moving smoothly again. Replace the plug and sticker, then carefully reinstall the fan in your machine.


It's now time to return to the components you took out of the PC and left to one side. Clean them individually with the soft brush, wiping away any excess dust. Hold the parts by the edges, being careful not to touch any contacts.

If you have a blower brush - a tool commonly used in camera cleaning - this will be an excellent tool for the task. When the kit has been cleaned, you can reassemble the PC.

step 7

Make sure the cards and memory chips are properly seated first, and if you removed any cables earlier, wipe them clean with a dry cloth and reconnect them. Have one final check to make sure they're connected firmly and correctly.

Remove any cleaning materials or obstructions before closing up the case. Leave the system to sit for 30 minutes, just in case all that blowing and wiping introduced any moisture.

Finally, connect the keyboard, mouse, monitor and power cable, with no other peripherals attached. Then switch on the machine to test that it's still working. If all has gone well, you should be able to enjoy a quieter, cooler and cleaner PC.

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