Cleaning the Inside of a Computer

Mike Halsey MVP
Jun 24, 2011
Updated • Dec 27, 2012

The insides of computers get dusty and grubby, it's just a fact of life.  Running all those electrical components builds up tiny static charges which draw in dust that clings to the circuit boards and metal structures inside the case.

There's no way around this either as your PC's case has to have vents and air-holes.  If it didn't the whole thing would overheat and, unless you had a very elaborate heat-pipe system in place, your computer would constantly crash.

The thing is though that with dust clogging up the innards of your PC it'll crash anyway, or at the very least heat up too much and be automatically shut down by your motherboard's BIOS to prevent the components melting.  As an example of this, just look at the processor heatsink in the photo below.  This was taken of one of my own computers just this morning.  Underneath the fan the processor heatsink it caked in thick layers of dust.  Under this circumstance the heatsink won't be able to vent any heat properly and the fan will just be something that spins around uselessly.

You can't escape dust from entering your PC either.  Some people say you should keep it on a desk or lifted up from the floor by a small stand.  These things, while they may delay the inevitable, can't prevent the build up of dust.  Other people say don't keep it on a carpet and instead try and put it on a laminate floor.  Laminate and wood floors are even worse though.  You may not get thick carpet fibres in the PC but at least a carpet can trap a lot of the dust in the room.  With a wooden floor there's nowhere for it to go except for inside your computer.

So we reach a point, as we all do from time to time, when you need to clean the inside of your computer, as I will have to do today.  I thought I'd share with you then my tips on the best way to do this.

First of all you should make sure that the computer is switched off and unplugged from the mains electricity supply before you take the side off the case.  You should then make sure that wherever you clean the PC, which should be in a place perhaps near an open door as it'll get messy, it should be well supported on a clean, flat surface.

pc cleaning

The best start is with a good strong puff of breath.  You'd be surprised how much dust this will actually clear.  Some people at this point may be inclined to stick a vacuum cleaner in the case, but first I'd recommend a small, unused, paintbrush.  This is a great way to get rid of most of the dust from the components themselves.

This won't get the dust up from the inside bottom the case though and won't help with the processor heatsink where you can't (or at least shouldn't) remove the fan.  Here you'll need that afore-mentioned vacuum cleaner.

You should always make sure, when using a vacuum cleaner inside a PC that you observe the following rules.

  1. Always use the vacuum on it's lowest suction setting
  2. Have a small, soft brush attachment fitted to the end of the hose

With these two rules in place you'll be able to gently brush over the components inside the case and remove the dust.  The processor heatsink can be more stubborn but for that I'd recommend the long thin nozzle attachment which you can point inside the fan to get at the dust directly.

You do need to be very careful when cleaning the inside of your PC as the components inside, especially those on the motherboard and plug-in cards are tiny and sometimes very fragile.  Always be very gentle and take your time.

You should normally do this with a PC a couple of times a year or so depending on where you keep the machine and how dusty it gets. Doing this will help prolong the life of your computer, help keep it operating at its maximum speed, help keep it quiet and probably most importantly have the side-effect of reducing your electricity consumption.


Tutorials & Tips

Previous Post: «
Next Post: «


  1. Bobby said on June 26, 2011 at 9:47 am

    I just chuck a bucket of water over it……….

    1. ima-pc said on September 20, 2011 at 7:13 am

      @Bobby – “I just chuck a bucket of water over it……….”

      ! i ! Safety TiP ! i ! : Unplug from power-source FIRST!
      Then check to be sure there is no nearby appliances
      IE: Hairdrier, Toaster, Lava lamp etc.. that is connected
      to a functional outlet – don’t know why, just heard that somewhere…
      Only then can you “just chuck a bucket of water over it”………SAFELY!!!

      GP TiP ! : When drying, toss blankets, towels, cat – whatever in
      with the computer, it will help keep the noise to a minimum
      [cat should quiet down within a minute or two..]
      AND set the heat on low better for the computer not to get too hot,
      toss in a few dryer sheets [static control & spring fresh scent]
      – an your good to go!
      While your at it, may as well clean that dirty monitor, mouse,
      keyboard, printer, webcam etc… , same process!

      BONUS TiP ! : Hang flypaper inside your tower, it collects the dust
      AND traps those pesky bugs that cause the dreaded BSOD!

      Remember; ~ A CLEAN COMPUTER is A HAPPY COMPUTER ! ~

  2. Jojo said on June 25, 2011 at 4:33 am

    I have filters on all the air intakes. This helps reduce the dust that gets into the case and the time between cleanings.

    Some time ago I brought a vacuum kit with small attachment tools and an adapter that fits a regular vacuum cleaner hose. This allows me to easily get into the small areas.

    I don’t know about modern vacuum cleaners but my old Electrolux cannister model has a reverse port that I can connect the hose to which turns it into a blower. I can blow the dust out the door or if I am too lazy to unplug everything, I get a big garbage bag and put it over the computer, then blow the dust out into the bag. I just wish I had a control to vary the power of the blower.

    Blowing out works particularly well for power units and to clean out between all the fins on the cooler.

  3. Jim Carter said on June 25, 2011 at 2:57 am

    I can’t find a reasonably priced air compressor that lasts more than 2 years. Now that I own a Metro Data Vacuum ED500 Datavac Electric Duster, I’ll never again consider an air compressor. I own a PC service company and I’ve cleaned dozens of machines with this product.

  4. Jyo said on June 25, 2011 at 2:05 am

    With desktops, this isn’t too complicated. But when it comes to cleaning out laptops….oh lord…. (no my cheap laptop doesn’t have a fan cover I can unscrew, which means I have to take the whole dam thing apart, which I gave up halfway due to fear)

  5. Berttie said on June 25, 2011 at 12:04 am

    I’d be wary of using an industrial compressor. Unless fitted with water/oil filters they can coat your electronic with a fine mist of both fluids.

    I use a long bristled 1.5″/40mm wide paint brush (natural bristles only) and an ordinary vacuum cleaner. I don’t let the nozzle actually touch any of the electronic components as nozzles can become highly charged with static electricity. Plastic nozzles are worse than metal ones in that regard. Just hold the end of the nozzle about 2″/50mm above where your cleaning and gently loosen the dust below with the brush.

    1. Mister M said on June 25, 2011 at 5:12 am

      Yes you have a good point there which i forgot to mention. So yeah, make sure any air compressor is relieved of any moisture. You can tell simply by what comes out of the nozzle. In a worse case scenario you would only have to completely drain the air tank once and wait for it to top up again

      thanks for the reminder

  6. Haakon said on June 24, 2011 at 9:05 pm

    Excellent article and one of the very few I’ve read over the years that doesn’t mention compressed air.

    Using a blasts of air is idiocy. While it does remove cosmetic buildup it also blasts everything into and all over everywhere. (And if you’re not wearing a contractor’s mask, your eyes, nose, mouth and lungs. Why don’t you just lick the floor while you’re at it?) Here’s a good way of looking at it: bust open a 10 pound sack of flour and whip it around all over your kitchen. Go get the vacuum cleaner or a leaf blower? Hmmmm?

    But if you’re lazy enough to use compressed air, you will spin fans way way way beyond their design RPM and will damage the bearings along with blasting crud into them. Don’t do that. Otherwise, blast all that crud and dirt to your heart’s content.

    Most vacuum cleaners come with a crevice tool. A drinking straw and some duct tape will let you make a nice tool for getting into tight spots.

    As for brushes, natural bristles are advised as the plastic ones can build up static. Since today’s vacuums use plastic I have 1/2″ and a 2″ paint brushes in my kit (and kept in a plastic bag) which I use in conjunction with the crevice tool.

    1. Fish said on June 25, 2011 at 12:28 am

      Ha-ha, thanks for the laugh, bud.

      Obviously, we dwell in different environments.

      I failed to mention that I live in a real small town where I have an infinite abundance of wide open spaces to do my thing. Here, cars, drains and us humans are more endangered suffocating from centuries of thick, seasonal barrage (just 2-3 months each year) of cottontree flotsam than anything else under the sun. All it takes is a spray of water to clear truck and air-con/heat pump radiator fins.

      Aside from my own, I have like a score of friends’ PCs to air-flush whenever yearly, and so far no bisons or Black Anguses (much less cooler fans) have complained.

      Yeah, for the rest of us though, I understand a little bit of creativity (whatever it takes) should help. I used to live in more densely populated Clifton, NJ, and I did manage without any hysteric trouble doing the same thing there. There was always a friendly patio under ’em apricot trees.

      Please, we have life-saving work to dig onto. My attention got pulled momentarily by the uncommon inference to “idiocy”, but I certainly don’t have any more time for it.

      Each is free to profess whatever he believes is right according to his experience.

  7. Fish said on June 24, 2011 at 8:40 pm

    I do it to every unit at least twice a year. Or, since it doesn’t take so much time anyway, two or three more times each one of them.

    For many years, I’ve been using only one piece of equipment which has never failed to do the job quickly or harmed my system in any way: the all-purpose 4.5A Metro DataVac Electric Duster. I bought it direct from the factory in New York, but it’s easy to find at Amazon if you’re not in U.S.A.

    Like Mister M above, I’d keep any fan from spinning excessively, but only when I’m cleaning such fan in particular.

    Long ago, I heard advice about electrical feedback risk especially with some PSUs, but so far that’s never occurred to any component of my PCs.

  8. Mister M said on June 24, 2011 at 4:02 pm

    i use an air compressor. not one of those pissy compressed air cans, a full-on 2.5HP air compressor ! it is quite safe, i assure you. just don’t do it too close to any motherboard components for risk of damaging them and also use a pencil-like utensil to stop any fans from spinning at superfast speeds or risk major electrical feedback damage to the motherboard, cpu, and the psu

  9. techandlife said on June 24, 2011 at 3:53 pm

    I think a lot depends how clogged with dust the machine is. If it’s really bad I’d take it outside and use a can of compressed air. Then brush out what’s left with a soft brush. More details here:

  10. Cohesus said on June 24, 2011 at 3:03 pm

    I do mine once every 6 months, i use a hoover to collect the dust but do dislodge it from the components i use a hand pump(kind you use on an airbed for example) i find this will dislodge all surface dust and no need to come into direct contact with components, also really good for getting dirt out of my keyboard.

    I have used a compressor in the past but find that to be a bit too violent causing fans to spin at high speeds.

Leave a Reply

Check the box to consent to your data being stored in line with the guidelines set out in our privacy policy

We love comments and welcome thoughtful and civilized discussion. Rudeness and personal attacks will not be tolerated. Please stay on-topic.
Please note that your comment may not appear immediately after you post it.