If you aren't aware, the BIOS is the "software" that runs when you first
power-up your system and forms the basis for how everything operates. In a
nutshell, it "tells" your computer where everything is, how to access it and
how to operate. Without a BIOS, your computer won't function.
Having said that, the info stored in the BIOS can be updated and sometimes
*needs* to be updated. This is done by means of "flashing" it. "Flashing"
your BIOS refers to updating the software that is stored in your CMOS.
Essentially, the process overwrites the current information and rewrites the
new information. This doesn't cost anything except in terms of time.
You'll need to download the latest BIOS from your motherboard's manufacturer
and install it.
However, there is a caveat. Flashing your BIOS is a risky procedure. If it
fails, it can leave your computer completely useless and, in many instances,
irreparable. It is usually recommended that you *not* update your BIOS
unless you are experiencing some problem which is resolved by the update or
the BIOS update introduces new functionality that you need (such as support
for new hardware.)
As far as doing it, it's a very straightforward process and your board
manufacturer's website should list instructions for performing the
operation.