Many people when building a computer will get all the necessary parts, hook them up correctly, screw everything in, yet forget about the necessity of good quality thermal paste to go on the CPU heat sink. CPU's are very sensitive to heat, and as such they need what is called a "Heat Sink" in order to transfer generated heat out from the processor through the attached fan. Heat sinks are generally made out of copper because copper is a very good heat conductor. All heat sinks, however, require something called thermal paste, which goes in between the heat sink and the processor. You can think of it as the cream that goes between two Oreo cookies. Thermal paste is needed to fill in the microscopic gaps that exist between the heat sink and processor when you attach them. You may not realize it, but even if the gaps are microscopic, it makes a huge difference in the temperatures.
Now most people will not have to go through the effort of applying their own thermal paste; most CPU fans on the market today have their own thin layer of it previously applied to the heat sink. For most non-gamers, this will be sufficient in cooling their system well enough to last years; but if you are a gamer that wants to get the most out of your desktop, the effort of carefully applying your own thermal paste can bring temperatures down by a lot, allowing the adventurous to go into overclocking territory. You will need a few things:
Please note that there are many different debated methods about the proper way to apply thermal paste. The following steps are only one possibility out of many, so try this first, and if you are not satisfied with the results, research a few other ways. There are also many different brands of thermal paste--for this try Arctic Silver 5--but the process is the same no matter which one you decide to use. Also make note that at no time during this process should your fingers touch the copper block, or the top of your processor, as the oils on your fingers create air pockets that will not be completely filled by the paste.
Note: Most brands of thermal paste require a "cure" time, which is the amount of time it takes for the contents to properly fuse together between the gaps in the heat sink and processor. It is still safe to run the computer like normal, but you may not see it reach its full potential until that time is up. Arctic Silver 5's cure time is roughly 500 hours as stated by the manufacturer. Also note that you cannot just wait out the 500 hours without going on your computer. The only way that the compound cures is by heating and reheating. So don't worry, and enjoy your cooler CPU!
Overclocking may sound like a scary concept to new PC gamers, but it can easily be simplified into a few safe steps to ensure that you get the most out of your system.