For starters, you should only update the BIOS for its causing you problems, and things arent working right. Secondly, go on the motherboards manufacturers website, and find the page about your board. In the download section it should list the bios revisions. There are easier ways, but its manufacturer dependant. For instance, with MSI the liveupodate program they have will tell you when theres a new bios out, and then will automatically update it for you.