Hmm, that's a slightly different scenario, but I'd still start the investigation in the same place: You can view, disable, and often remove unwanted or unknown '''extensions''' on the Add-ons page. Either: * Ctrl+Shift+a (Mac: Command+Shift+a) * "3-bar" menu button (or Tools menu) > Add-ons In the left column, click Extensions. Then cast a critical eye over the list on the right side. All extensions are optional. If in doubt, disable. If you don't remember adding it, remove it. '''Recently an extension named SafeSearch Incognito or SearchAssist Incognito (or similar) has been identified by other users as hijacking all searches to Bing, even from Google's home page.''' Often a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step. Any improvement?