How to Clear History, Cookies and Cache in Mozilla Firefox
Learn how to periodically delete the history, cookies, cache and stored data in Mozilla Firefox to protect your privacy on the computer, troubleshoot problems with the browser and perhaps improve your browsing performance. Add this process to your regular computer maintenance schedule to prevent problems with the computer.
Turn on your computer and launch the Firefox Web browser.
Click "Tools" in the menu bar at the top of the screen. Select "Clear Recent History" from the drop-down menu.
View the Clear All History pop-up window. Select "Everything" next to "Time range to clear."
Place a check mark in the box in front of each of the first five categories: Browsing & Download History, Form & Search History, Cookies, Cache and Active Logins.
Click the "Clear Now" button.