By modern standards, a 1.60 GHz processor is pretty slow. Most machines that run at this speed are either older computers or netbooks. That's not to say that these processors can't be made to run faster, because you can overclock a 1.60 GHz processor to an almost infinite speed, assuming your motherboard can support the extra workload and you have sufficient cooling.
Reset your computer and enter your PC BIOS. This is done by pressing a particular button (the button varies with the computer model) when your computer first boots. The button you will need to press (usually either F6 or F12) will be visible at the top of your monitor when your computer first turns on. You will only have a few moments to press the button before your computer boots into your operating system.
Locate your CPU settings. The label may vary somewhat from one BIOS to another, but it will usually read something like "CPU Settings."
Highlight the FSB, or "Front Side Bus," option and press the "Enter" key to open a smaller window that allows you to enter a numeric figure.
Increase the Front Side Bus speeds by small increments. You can estimate the projected processor speed by multiplying the FSB speed by the CPU multiplier, which will be visible on the same screen though will not be able to be edited. For a 1.6 GHz processor running with a 200 MHz FSB, the multiplier would be X8. By increasing 200 MHz to 250 MHz, the CPU clock speed would increase to 2.0 GHz.
Increase your CPU voltages to compensate. A marginal increase in power requires only a marginal increase in voltage.
Exit out of your BIOS, saving your settings as you do, and restart your computer. Let the computer boot into your operating system.
Run your benchmark software once your OS is loaded. This will test your computer's new settings, checking them for stability. If there are issues, the benchmark software will inform you and you can return to your BIOS and adjust the options accordingly. A variety of benchmark programs can be found in Resources.
Some processors will allow you to overclock by adjusting the multiplier. This is only available in what are considered "enthusiast" processors, which cost more, but are marketed to overclockers.
Depending on how much you intend to overclock your processor, you may want to consider purchasing a new heat sink or more tower fans to keep the PC case interior cool.
Overclocking your processor will void its warranty, and improperly overclocking any piece of hardware can ultimately damage it.