What do you mean with "Firefox toolbar" -- do you mean the entire UI of Firefox, including menus, or do you just mean the default list of bookmarks that came with Firefox? It sounds like you have installed the Spanish version of Firefox at some point, either in the past or recently. If this is a fresh install, I would advice you to reinstall Firefox and be sure to pick the English version from www.mozilla.org/firefox. You will also need to create a new profile, since your bookmarks and other settings will be kept even if you reinstall, so they will otherwise remain in Spanish. See here for info about how to create a new profile: https://support.mozilla.org/en-US/kb/Managing-profiles?s=profile&r=0&e=sph&as=s