Method
Now to explain how to actually overclock your system. There are really only two ways to overclock an Intel processor: raise the FSB, or raise the Multiplier. Far and away the easiest way to overclock is by raising the multiplier. Bump the multiplier up to 20 and there you go, you got your extra 1000MHz clock speed. Oh how nice that would be. Unfortunately for us, multipliers are typically locked, especially on current Pentium 4 chips. So that leaves us with one option: raising the FSB speed. The ONLY way I would go about raising the FSB speed is through your computer's Basic Input/Output System (BIOS). There exist some third party utilities that let you raise the FSB of your CPU, but to be honest, those seem sketchy at best.

The important thing to remember about your BIOS is that not all BIOSes are created equal. Some BIOSes, like those found in Dell computers, are severely crippled excuses for a BIOS that are designed specifically to prevent inexperienced users from messing around with some settings that could prevent the computer from working properly. Other BIOSes will let you change just about anything and everything. From an overclocking standpoint, there are basically three different kinds of BIOSes: good ones, bad ones, and in between ones. Overclocking can sometimes be a very precise art, with ever-so-slight adjustments meaning the difference from success to total system failure. As such, a BIOS with loads and loads of features will always be ideal for an overclocker. Unfortunately, you can't just go around choosing which BIOS you will be using. Motherboard manufacturers choose which kind of BIOS to implement on their motherboards, so you are pretty much stuck with whatever kind they ended up using. The good news is you can buy motherboards from certain manufacturers that do indeed use fully functional BIOSes on their products. Such manufacturers include MSI, ASUS, and DFI, to name a few.

Starting Out
OK so you know what FSB is and you know what you are trying to do, now it is just a matter of doing it. First thing's first: familiarizing yourself with your tools. To do this you should restart your computer and find out what button it asks you to push to get into “setup”. It is usually delete, but it could be F1 or F5 or any other function button for that matter. Once in the BIOS, locate what should be called “advanced chipset features”. Look at all of those options and even play around with them. Raise the FSB of your CPU, mess around with the 'vcore' and 'vdimm' voltages, have fun – it won't do anything to your computer unless you save those settings to your CMOS before exiting the BIOS. Which brings me to my next point: If you are messing around in the BIOS, DO NOT SAVE SETTINGS! Next thing you should familiarize yourself with are the characteristics of your CPU and RAM. You can do this by downloading a utility called CPU-Z. The things to note about your system in CPU-Z are your voltages. You should make sure to write down the stock (what your initial readout should be unless you have overclocked already) voltages so that you can use that as a reference as you overclock. You should also be aware of where the CMOS jumpers are on your motherboard. They are usually located next to the CMOS battery, which is a flat, round battery about the size of a quarter. One last thing you want to know about is the temperature of your processor. It is also beneficial to know other temperatures in your system, and there are utilities, such as Motherboard Monitor 5 and Speedfan, that will let you do this with ease. It is important that you know the limits of your particular system. These utilities should be running every time you use your computer so you can constantly keep an eye on your temperature.