Just type "system information" into the search bar and under system summary you'll find the bios version.
Head to the motherboard manufacturer’s website, find and download the latest version of bios for your specific motherboard, unzip it into the root folder (base folder) of a usb thumb drive and plug in into your motherboard. from this stage onward you can either use the EZ Flash 2 utility in your bios or through bios flashback button on your motherboard itself.