depending on your bios you may or may not have the option if your mainboard is attached to a name brand PC like gateway,compaq,dell ect ect then your out of luck if its not one of those look in your BIOS and set your settings to user define and then see if you have settings to adjust, if this is your first try at overclocking please read the tips section and other relating articles and you'll end up with a much better PC
OH i almost forgot
WELCOME TO THE FORUM!