In the top-right corner of the browser window, click the Library button , choose History, and then Clear Recent History.
Note : If the library button doesn''t exist, click the Menu button
Select how much history you want to clear:
1. Click the drop-down menu next to Time range to clear to choose how much of your history Firefox will clear.
2. Click the arrow next to Details to select exactly what information will get cleared.
Finally, click the Clear Now button. The window will close and the items you''ve selected will be cleared.

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