Cleaning your computer
Many problems I see are related to overheating. Such as CTDs, video artifacts, sudden freeze which may or may not recover (not stuttering which is a very short pause)
The design of the PC contributes to this by sucking in dirty air through every small crevice in the case and depositing the dust on everything, especially fans.
To clean the pc, first power it off and UNPLUG it. There is power on your motherboard (5 volts)even when the power is switched off and a mistake can fry your motherboard and Power supply.
Most newer tower type PCs have a removable side, the left side when looking at the case from the front. Usually there are anywhere from one to three screws that hold it in place. remove the screws and slide the cover to the rear slightly to release the locking tabs, then lift the cover off.
Now, look inside and see how much dust has accumulated. check the heatsink and fan on your processor ( usually mounted near the center of the motherboard.) The chassis exhaust fans, the power supply vents and if your graphics card has one, the fan and air channels there.
If you haven't cleaned in in the last six months it's probably pretty dusty. All of that dust is preventing proper cooling and may be contributing to problems such as slow downs, CTDs, video artifacts and freezes.
If you have determined that you do need to clean it. Unplug everything from the case - It's a good idea to label each cable as you disconnect it, and draw a picture showing where each goes. Also make a drawing of all of the connections inside the case so if you do unplug something you will be able to put it back when you are finished.
Now take your case to a place where you won't get the dust all over the rug in front of the computer to be sucked back in - outside is best.
If it is available, the best thing to use is LOW pressure compressed air. Less than 50 PSI. High pressure can damage components and blow connectors loose. I have seen high pressure air actually peel a trace off of a circuit board. If you don't have access to an air compressor, You can get cans of compressed air at most places that sell computers (Wall Mart, Best Buy etc.) many vacuums have a blow option that will work. be sure to use the tool with the smallest opening for best results. If your vacuum doesn't have a blow, use the suck, to clean it. Again with the tool with the narrowest opening (usually called a crevice tool)
A paint brush, either 1/2 inch or 1 inch wide can be used to brush the places where the dust is not coming off. Preferably use a natural bristle brush over a plastic bristle. Camel hair is the traditional choice of old electronics techs who claim that plastic bristles, especially nylon, can generate static electricity that can damage sensitive electronics. I've never actually seen that happen, but I still prefer my 35 year old camel hair brush.
Pay particular attention to the small spaces between the plates of heat sinks (be careful not to bend the plates), air channels and places where air enters the case - like around USB ports and other ports on the front and back of the case. Be sure to clean out the power supply as best you can without opening it up. Use the brush to clean fans and air intake grills. Don't expect to get every speck of dust off, It just isn't possible.
Some cases have filters, usually mounted in the front of the case near the bottom. Take the filter material out and clean it thoroughly. You can wash it, but be sure it is thoroughly dry before putting it back in.
Before putting the cover back on press down on all of the cards to be sure they are properly seated in their sockets, take another careful look to be sure everything is plugged in that is supposed to be (remember that drawing?)
Don't forget your keyboard and mouse. Turn the keyboard upside down and shake it to remove the large particles. Then use the vacuum and brush to clean out the dust and smaller particles. If it's very dirty, use a mild kitchen type spray cleaner, DO NOT spray it directly on the keyboard. Spray it on a paper towel or soft cloth and wipe the keyboard. Modern laser mice no longer have the aggravating ball that used to need periodic cleaning, but they do have a scroll wheel that can get dirt inside, use the brush to clean as beat you can and again wipe it down with a cloth or paper towel that you sprayed with the cleaner. This might be a good time to replace the batteries in your mouse and keyboard if they are wireless.
I have seen others advocate putting the keyboard in a dishwasher. This works - I have done it. However, This is a last resort for when something has been spilled into the keyboard and regular cleaning does not work - keys stuck and not responding or just not working. This MAY save a keyboard, but be prepared to replace it anyway. Also. give the keyboard 3 DAYS to dry. NO LESS. And turn it over every day while it is drying. If it is a cordless keyboard, Be sure to remove the batteries first.
Your DVD/CD drive should be dusted as well as you can, the laser on some is exposed when the drive door is open, you can wipe it clean, but don't press hard. On most it's inside the drive where you can't get to it. If you are having a problem, there are commercial DVD/CD cleaning gadgets. They look like a CD and will wipe the dirt (or orange juice) off of the laser that reads the data.
In case you are wondering, Orange juice or beer, or soda gets on the read laser when you place a CD in a puddle on your desk, then insert it into the drive. Children, and some adults, do this all of the time.
Now, with the side back on and screwed on tight, using the drawing and the labels you put on all of the cords, reassemble your computer in it's proper place. Double check all cords before plugging it back in. Now power up and check everything to make sure it all works.
Headsets, VOIP phones and any other gadgets you have attached to your computer can be cleaned the same way. Do not spray the cleaner on the item, spray it on a cloth and use that to wipe it down.
Monitors can be dusted and vacuumed, Be sure to turn them off first.
Use a mild cleaner agent and wipe down the casing, especially the top as this is where most of the dust tends to be. Don't spry it directly, spray the paper towel or cloth. Don't put too much liquid on the cloth where it might drip through the holes and into the computer monitor. Use low pressure air or a can of air and blow in the holes to get the any dust that may be in there out. Or you can use a vacuum cleaner and suck the dust out. The face of a CRT monitor can be cleaned with any glass cleaner.
LCD or flat Screen – Don't use glass cleaner.
Also, Don't Use a paper towel or dirty cloth. They can easily scratch the screen, also using methyl chloride, acetone, ethyl acid, ethyl alcohol or ammonia-based cleaners can damage the screen, LCD monitors are especially sensitive to these chemicals. You will get a PERMANENT blur effect or worse.
Dampen a clean soft cotton cloth with clean water and gently wipe the screen starting from the top of the screen to bottom wiping in a downward motion. Be careful not to press too hard or else you may damage the screen.
I'm not going to get into printers or scanners as that is another bucket of worms. Read the manual for cleaning instructions on your particular device.