How to Clean a Desktop PC

When it comes to PC performance, dust is your enemy. Dust collects in and around your desktop due in part to the constantly moving air being drawn in by the cooling fans used by the PC to keep various components running at safe temperatures. This dust collects and forms an insulating blanket over the components, air vents, and even the fans themselves.

This is one of the many reasons you want to perform regular maintenance on the PC. Overheating can cause a number of issues including decreased performance, shorter system life, and in some cases even a short which could result in a fire hazard.

In general, you want to clean your desktop PC inside and out every season. If you have cats, this might be a worthwhile monthly endeavor as cat dander has a way of getting into everything.


There are many different ways to clean a computer, and it comes down to personal preference as to how you personally want to go about doing this. The most important thing to remember is that water is your enemy, the system should be unplugged, and you should never use anything made of metal on any exposed internal components. The motherboard is especially sensitive to this, so take care around this particular system component.

Here are some things I use when cleaning a desktop PC:

  • Can of Compressed Air (refrigerant-based propellant cleaner)
  • Blow Off Electronics Cleaner (Foam)
  • Rubbing Alcohol
  • Water
  • Cotton Swabs (Q-tips)
  • Microfiber Cleaning Cloths

The compressed air is used to get the bulk of the dust out of the case. Keep in mind that this means that very dust will fly around the immediate area you’re cleaning in, so doing this part outdoors is certainly recommended. Just don’t do it on a rainy or particularly humid day.

What we refer to as compressed air is actually a chemical solution and not so much the result of an air compressor. The air we breathe is filled with moisture and this moisture can be harmful to system components.

Opening the Case

Before doing anything inside your case, you’ll want to make sure your computer is turned off and unplugged from anythings and everything. This is always a job best done away from your normal computing environment as well. Perhaps on a covered table on the porch or in the garage. It can get pretty messy, and you really don’t want all that excess dust floating around the very room you intend to put the computer back into.

Opening the case can be done in a variety of ways, depending on the case itself. Some computer cases have screws that hold on a side panel, while others might have latches, buttons, or knobs that you can turn without the need of a screwdriver. In any cases, one of the panels along the side of the computer should come right off, giving you full view of the internals.

Another side panel might be more difficult to remove, though you should remove it as well in order to get at dust sitting under the motherboard and/or back plate. This panel is most often fastened with two screws that run along the back of the case.

You may even want to remove the front panel from the case as well, though this isn’t always necessary. Older computers would collect dust in this area, but a good spray of compressed air usually frees this up and blasts it out one of the side panels.

Cleaning the Interior

This is the fun part. In a well-ventilated area (preferably outdoors) give your computer a thorough once-over with the compressed air. An actual air compressor would be handy here, though a can of moisture-free compressed air is typically safer for your system. Apply the air over the main body of the interior, then work your way into crevices and other hard-to-reach spots such as that space between hard drives or around the DVD-R.

If you use the air in bursts rather than just holding down the trigger, it will last longer. As the can is used, it gets cold due to the chemical reaction. Once the can gets cold enough, you’ll notice a decrease in air pressure. Give it a break now and then and allow it to settle before continuing. I usually have two or three cans on-hand for a case clean out so I can switch between them as needed.

Remember to keep the tip of the can about four inches away from any components. Even in moisture-free cans, there is a potential for moisture build-up around the cool air. Also, avoid tipping the can as it will release the chemicals which themselves are extremely cool and moist. If you keep the can upright, you should be spraying just cool, dry air.

If you encounter stubborn dust or debris, you may want to take a cotton swab to it. Make sure you’re using a Q-tip style swab rather than a cotton ball as the loose fibers can snag and collect on the interior components. It’s OK to blow compressed air into the power supply. In fact, this may be the biggest collector of dust in the entire system.

I usually leave the bottom of the case last as it is usually covered in dust after the upper-most components are cleaned. Give it a good burst, aiming the stream out of the case so the dust doesn’t blow back inside.

Never use a vacuum cleaner on the inside of a computer as this could introduce a static charge which may damage internal components. Unless the device is made specifically for electronic components, it doesn’t belong inside an electronic device.


Compressed air can work on the exterior of a case, but you do have a little extra leeway here in terms of moisture. Rubbing alcohol is a great cleaning agent, and it usually dries very quickly. This, combined with a cotton swab or cleaning cloth, can make short work of cleaning the air vents found on the exterior panels.

Run a damp cloth over the exterior of the case (unattached to the section holding internal components) and let it dry before reassembling your system. At this point, you should have a clean interior, exterior, and everything should be absolutely dry.

Reconnect your cables (power cable last) and fire the system up. Everything should run as if nothing happened, though you may notice the internal operating temperature drops a bit as the insulating dust is now completely gone. Three-six months from now, you’ll want to do this all over again.

12 comments On How to Clean a Desktop PC

  • Take care to stop fans from turning with a q tip or your finger when using compressed air on them. The compressed air can spin them much faster than the motors would and can really wear them out.

    It’s good that you mentioned the “canned” air is safer for your system. A lot of people miss that. Most air compressors get moisture built up inside (the compression squeezes it out of the air) and people forget to drain them all the time. A lot of times there is a little oil in them to prevent rusting and that comes out the nozzle too.

  • Something that I discovered a while back is that for getting the outside of an old pc (or game console) cases clean nothing works as good as a Mr Clean Magic Eraser, made a 20 year old Nintendo look brand new.

  • great advice for  a tower, for a laptop not really possible to clean out…… (if you dont want to void your warranty) and a bit of a pain to reassemble (i used to  fix laptops) 

  • allways said keeping the PC cabinett on the floor is a bad idea :p.

  • Thank god I don’t use desktops anymore. Brought the last one to the local dump a couple of weeks ago. Just before I went, I opened it up, to make sure I’d removed the HDD. The inside was just NASTY! 

    But great tips for the people who still own and use a desktop these days though…

    • laptop are not as powerfull as desktops XD but then againg peaple like me who run desktops for gaming clean it out XD

    • A lot of times there is a little oil in them to prevent rusting and that comes out the nozzle too. My ńeighboŕ’s mŏther-iń-ląw Maḱes $8O houŕly on the laptoṗ. She has bėėn out of w0rḱ for 7 Ṁonths but ląst Ṁonth her ińcome wąs $8734 just worḱińg on thė laṖt0Ṗ for a ƒew hours. Gŏ to this web siṫe and ŕead morė.. CashLazy&#x2Ecom

  • Where I live (Costa Rica, tropical) there is the problem of large solitary ANTS (called “Bala” or “Ghost” ants) that look for a warm spot to build their “nest” which is a glob of what they use to grow a fungus which is their diet.  The colonies are usually small, 100-200 adults and about 100 eggs.  That GLOB is so acidic that it quickly eats away the copper traces on PC boards and even can eat thru small wires found in electronics and they also plug up the ventilation holes and slots to keep warm..  So, Rule #1, if you have ever even seen an ant near your electronics, when you bring your new toy into your house, open it up enough to be able to puff in some Ant & Termite Killer (Zep Professional works well) into the bottom of the case.  And after your LG recommended semi-annual cleaning, puff in some more, just to make sure, otherwise, the consequences can be disastrous!

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