Do you still have a BitDefender directory in program folders, usual location is C:\Program Files\BitDefender\ If the directory still exists, the uninstall did not complete fully. BitDefender recommend downloading the uninstaller and running it again. You can get the uninstaller from http://www.bitdefender.com/uninstall If that does not work, you can try manually removing the toolbar. Do you have a folder called C:\Program Files\BitDefender\BitDefender 2009\FFToolbar The "BitDefender 2009" part will vary depending on the version of BitDefender installed. If that still exists try deleting the contents of the FFToolbar folder. BitDefender is likely to have added an entry to the Windows Registry, if you are happy with editing the registry you can remove the entry, for details see the "Windows registry extension" section of http://kb.mozillazine.org/Uninstalling_add-ons '''Warning: Only edit the registry if you know what you are doing, making an error in the registry can cause serious problems with Windows, it may even prevent Windows from starting.'''