How to Uninstall Firefox in Windows 7
Mozilla Firefox is a feature-rich alternative to Windows 7's default Internet Explorer, but it is not for everyone. If you decided to give Firefox a try but do not want it installed anymore, you can uninstall it from Windows 7 through the Control Panel. This will remove all components of Firefox, including history, bookmarks and add-ons.
Close Mozilla Firefox. If you receive an error that Firefox is still running, right-click the Windows taskbar, and select "Start Task Manager." Click "Firefox" in the list of running processes and click "End Process." This forces Firefox to end.
Click the "Start" button, and type "uninstall a program" (without quotes).
Click "Uninstall a program" in the search results.
Click "Mozilla Firefox" in the list of installed programs.
Click "Uninstall" at the top of the program list, and click "Uninstall" again in the confirmation window.