The first step is to find out if there is an update available for your BIOS. To do this, when your computer boots up, try to look at the information presented to you. You should get a list of drives detected, your computer's processor identification, the amount of RAM in your computer, and most importantly, the version of your computer's BIOS. You might have to restart a couple of times before you can find the version of your BIOS. If you see a fancy graphic coming up during bootup instead, you should try pressing the "Delete", "F2", "F10" or "Tab" on your keyboard during bootup. Chances are, one of these keys will show you the real information string instead of that fancy logo.
If you're too lazy to do this, download an application called EVEREST by Lavalys. This software will present you with a goldmine of information about the innards of your computer, including the BIOS version you're running on your computer.