You can look at these prefs on the about:config page. *http://kb.mozillazine.org/browser.history_expire_days (180) (also affects saved form data) *http://kb.mozillazine.org/browser.history_expire_days_min (90) To open the <i>about:config</i> page, type <b>about:config</b> in the location (address) bar and press the "<i>Enter</i>" key, just like you type the url of a website to open a website.<br /> If you see a warning then you can confirm that you want to access that page.<br />