Hello bayvu2, it seems like there has been a problem during the installation of your Firefox web browser, because it shows up as version 3.6.28 (at least when you posted) and you claim to have installed Firefox 12.0. You should try reinstalling Firefox from the official [https://www.mozilla.org/en-US/firefox/new/ Mozilla Firefox website]. Thank you for your patience and all your interest in Mozilla Firefox and please let me know how it goes and mark my answer as a solution if it resolved your issue.