How to safely clean a PC - dos and don'ts

Dust buildup is one of the most overlooked causes of PC problems. It insulates components, restricts airflow, and quietly pushes temperatures up over months until things start going wrong. Cleaning your PC is straightforward - but there are a few ways to do it badly.

What you'll need

• A can of compressed air, or a purpose-built electric air blower
• Isopropyl alcohol (90% or higher)
• Cotton swabs or lint-free cloths
• A soft brush (a clean paintbrush works fine)
• An anti-static wrist strap if you have one - not essential but worth using

Avoid regular household cloths, paper towels, or anything that sheds fibres. Avoid WD-40, water, or any cleaning product not specifically rated for electronics.

Before you start

Power the PC off completely and unplug it from the wall. Don't just put it to sleep - cut power entirely. Wait a minute or two for capacitors to discharge.

Work somewhere with decent ventilation. Blowing dust out of a PC in a small enclosed room just means breathing it in and some of it settling back down.

If you're going to be handling components, touch a metal part of the case before you start to discharge any static. A wrist strap clipped to the case gives you continuous grounding while you work.

Do: blow dust out, don't vacuum it up

Compressed air is the right tool. Work systematically - start from the top of the case and work downward, so dislodged dust falls away from components you've already cleaned rather than onto them.

Hold fans still while blasting them. Spinning a fan with compressed air can generate voltage back through the circuit and damage the fan controller or motherboard header. Hold the blade with a finger or a pencil while you clean.

A vacuum cleaner is risky near electronics - the nozzle can build up a static charge and discharge it into a component. Use compressed air to dislodge dust, then vacuum the floor afterwards if needed.

Do: clean the filters

Most modern cases have removable dust filters on the intake fans. These catch the bulk of debris before it gets inside. Take them out, rinse them under a tap, let them dry completely before refitting, and do this every couple of months. Clean filters make everything else easier.

Do: clean the heatsinks properly

The CPU cooler and GPU heatsink are where dust causes the most damage - it packs into the fins and creates an insulating layer that traps heat. Use short bursts of compressed air at an angle to force dust out through the fins rather than further in. A soft brush helps dislodge anything compacted.

If you're removing the CPU cooler for a deeper clean or thermal paste replacement, clean the old paste off both the heatsink base and the CPU lid using isopropyl alcohol and a lint-free cloth. Dried thermal paste looks grey and chalky - if it's crumbling or cracked, it needs replacing regardless.

Do: clean the GPU

The GPU usually collects the most dust in a system. If the fans are accessible, hold them still and blast air through the heatsink from multiple angles. For a thorough clean you can remove the GPU from the PCIe slot - it's two screws and a clip - which makes it much easier to clean properly and check the fans are spinning freely afterwards.

Don't: use compressed air in long bursts

Short, controlled bursts. Long continuous blasts can cause the propellant in the can to release liquid onto components. Keep the can upright and use bursts of no more than a second or two.

Don't: touch PCIe gold contacts or RAM sticks with bare fingers

Skin oils on the contacts of a GPU, RAM stick, or M.2 SSD can cause connection issues. If you need to handle these, hold them by the edges. If you've touched the contacts, a wipe with isopropyl alcohol on a lint-free cloth will clean them up.

Don't: reassemble while anything is still damp

If you've used isopropyl alcohol anywhere, make sure it's fully evaporated before powering back on. IPA evaporates quickly - a minute or two is usually enough - but give it longer if you've used it liberally.

How often to clean

Every 6-12 months for most setups. More often if:

• The PC is on the floor rather than a desk
• You have pets
• The room is dusty or the PC runs in an area with poor airflow
• Temperatures have been creeping up over time

A quick clean every six months takes 20 minutes and can extend the life of your components significantly. The cost of a can of compressed air is considerably less than a new GPU.

When to send it in

If you've cleaned the PC and temperatures are still high, the issue is likely dried thermal paste on the CPU or GPU rather than dust. Repasting is straightforward but does involve removing heatsinks and, on a GPU, sometimes the shroud as well.

If you've found corrosion, burn marks, or bulging capacitors during your clean, stop and get it looked at before powering back on. We can assess component-level damage and advise whether a repair is worth doing before anything fails further.