Firstly, let's go through the steps of cleaning your computer's inside, then we'll discuss the benefits of the exercise.
TOOLS NEEDED: Star and flat screwdrivers, new 2 inch paintbrush, old toothbrush, air blower, soft damp cloth.
1. Remove any CD's, DVD's, stiffies, flash drives, etc from the drives.
2. Switch the power off and unplug the computer from the wall outlet.
3. After making a careful note of where all the plugs and cables are connected, unplug all the rear cables, and then take the computer to a table outside (or where the light is good), and where you can make a lot of dust. Using the air blower, blow the dust off the outside of the computer case, especially the back connections.
4. Take the cover(s) off the computer case. Usually there are two or more screws at the back, and then the covers slide off rearwards, but there are so many different types of cases, you may have to figure out how they come off!
5. With the air blower, start blowing from a distance of about 2 feet and gradually move closer as needed, being careful not to blow the computer components to bits. You want to remove the dust, not sandblast the thing. Pay special attention to any fans, and also to the main CPU. The main CPU should have a large finned heat sink attached to it, which becomes caked with dust.
6. Once you have blown the worst of the dust off, use the air blower and the paint brush to dust off stubborn caked dust, especially on the heat sink of the CPU, on the fan blades, and around the Power Supply Unit, which is the metal enclosed box where the mains plug goes in. Don't forget the fan at the back of the computer. Using the paintbrush you can get to the fan quite well through the inlet vents.
7. If there is any dust that is too caked to get off with the paintbrush, use the old toothbrush to gently brush it off.
8. Once all the dust is gone, use the soft damp (NOT wet!) cloth to wipe down the outside of the computer case and the loose covers.
9. Put the covers back, take the computer and air blower back inside and connect all the computer's plugs up. Check that they are all correctly and firmly inserted, and then switch the computer on again.
10. Open the CD/DVD drawers and using the air blower, blow into the drawers to remove any dust that may have got into there. DVD players don't like dust on their internal lenses.
BENEFITS OF AN INTERNAL CLEANUP:
Computer CPU's (Central Processing Unit, the "brain" of the PC) generate a lot of heat, due to all the processing going on in their integrated circuits. The finned heat sink mounted on the CPU transfers heat from the CPU to the surrounding air by creating a large surface area (that's what all the "fins" are for.) If this surface area is covered with dust, it traps the heat and the CPU overheats, shortening it's life span.
In the same way, if the fan blades and inlet vents are caked with dust, this reduces the amount of air that can be sucked in to the computer and over the CPU heat sink, so the computer will run at a higher temperature than it should, which will shorten the life of the various components in the computer.
CD and DVD players are very fussy about dust. A few specks on the laser lenses can cause a lot of problems when reading and writing data, in some cases the machine will reject the disk as unreadable.
If you live in a warm climate, this should be done fairly often.
A clean computer should give you many years of trouble free service.