Hi tejalsolanki, It's very simple. Go to ''Tools'' , then to ''Clear Recent History.'' If you need to do this in the future, press ''Ctrl + Shift + Delete.'' The delete key is the one at the end of the keyboard, '''NOT''' the erase button, backspace. Meanwise, When you press ''Clear Recent History,'' uncheck everything except ''Active Logins'' . If you also don't want firefox to remember what you searched (example; Google/Yahoo) check ''Site Preferences'' too. You can always contact the Live Chat Support, (not 24/7) and feel free to ask any further questions!