You should check with Avast for an updated version of their Firefox extension. Personally, I quit using Avast a few years ago and switched to Avira Personal Free - http://www.free-av.com/ . Compatibility with Firefox shouldn't be an issue with AntiVir, as they don't install any silly extensions in Firefox. <br /> '''Correction:''' Avira '''''didn't''''' install any toolbars for Firefox until 06-28-2011, the AV10 SP2 update has a new feature called WebGuardm that includes the Avira Search Free Toolbar that is from Ask.com, You need to uninstall the WebGuard to get rid of the Search Toolbar.