I like to visit my frequently accessed webpages by beginning to type the address (ie. "sub" to get to my youtube subscriptions or "f" to get to facebook).
Now, out of nowhere, this awful Bing search comes up ( with the magnifying glass symbols) first and blocks my normal drop down menu. "Sub" brings up the Subway menu search option in Bing. I am highly irritated. I do not want Bing forced on me.
Try Firefox Safe Mode to see if the problem goes away. Safe Mode is a troubleshooting mode, which disables most add-ons.
(If you're not using it, switch to the Default theme.)
On Windows you can open Firefox 4.0+ in Safe Mode by holding the Shift key when you open the Firefox desktop or Start menu shortcut.
On Mac you can open Firefox 4.0+ in Safe Mode by holding the option key while starting Firefox.
On Linux you can open Firefox 4.0+ in Safe Mode by quitting Firefox and then going to your Terminal and running: firefox -safe-mode (you may need to specify the Firefox installation path e.g. /usr/lib/firefox)
Or open the Help menu and click on the Restart with Add-ons Disabled... menu item while Firefox is running.
Once you get the pop-up, just select "'Start in Safe Mode"