To flash your bios you need to go to the website of your manufacturer. There they will ask you what MOBO you have in the downloads section. What you want to do is find the latest 'revision' for your MOBO.

With mine it gave me a "utility" to make the Bios-Flash Disk, and I followed the instructions to "flash" my BIOS which basically brings you MOBO up to snuff. It helps your MOBO better communicate with all your system devices.