Tips to keep your PC cool

Check air flow

The easiest thing you can do to help keep your PC cool is to give it a little breathing room by removing any obstacles to air flow.
Make sure there’s nothing sitting right against any side of the computer, especially the back. Most of the hot air flows out of the back end of the computer case. There should be at least 2 to 3 inches open on either side and the back should be completely open and unobstructed.

Keep Your PC Cabinet Closed

If the case is open there will more open space for debris or dirt. When the case is left open, dust and debris clog the cooling fans faster than when the case is closed. This causes the fans to slow down and fail much quicker than usual. A clogged up fan does a terrible job at cooling your expensive computer components.

Clean Your Computer time to time

The fans inside your computer are there to keep it cool. Do you know what slows a fan down and then eventually makes it stop? Dirt – in the form of dust, pet hair, etc. It all finds a way into your computer and much of it gets stuck in the several fans.One of the most effective ways to cool your PC is to clean the internal fans. There’s a fan on top the CPU, one inside the power supply, and usually one or more on the front and/or back of the case.Just shut your computer off, open up the case, and use canned air to remove the dirt from each fan.

Upgrade the CPU Fan (Cooling Fan)

Unless you’ve replaced your CPU fan already, the one that’s in your computer now is probably a bottom-of-the-line fan that cools your processor just enough to keep it working properly, and that’s assuming it’s running at full speed.Many companies sell large CPU fans that help keep CPU temperature lower than a factory installed fan ever could.Shop around for a CPU fan that’s compatible with your CPU socket. Just about anything is going to be better than what came preinstalled in your computer.

Install a PC Exhaust Fans (or Two)

A case fan is just a small fan that attaches to either the front or the back of a computer case, from the inside. Case fans help move air through a computer.Installing two case fans, one to move cool air into the PC and another to move warm air out of the PC, is a great way to keep a computer cool.Case fans, of which there are many to choose from, are even easier to install than CPU fans so don’t be afraid to get inside your computer to tackle this project.

Replace the Power Supply (SMPS)

The power supply in your PC has a large fan built into it. The air you feel when you hold your hand behind your computer is from this fan.If you don’t have a PC Exhaust Fans, the power supply fan is the only way that the hot air created inside your computer can be removed. Your computer can heat up quickly if this fan isn’t working.Unfortunately, you can’t just replace the power supply fan. If this fan is no longer working, you’ll need to replace the entire power supply.

Install Component Specific Fans

It’s true that the CPU is probably the biggest heat producer in your computer but nearly every other component creates heat as well. Super fast memory and high end graphics cards can often give the CPU a run for its money.If you find that your memory, graphics card, or some other component is creating a lot of heat, you can cool them down with a component specific fan. In other words, if your memory is running hot, buy and install a memory fan. If your graphics card is overheating during gameplay, upgrade to a larger graphics card fan.

Source: http://pcsupport.about.com/od/maintenance/tp/pc_cooling.htm