Hi koos. From the Menu Bar, Tools -> Options -> Privacy. Change the "Firefox will" dropdown to "Use custom settings..." Then uncheck "Remember download history" Or if you wanted to clear download history when Firefox closes, check the "Clear history when Firefox closes" checkbox, and from the Settings button to the right, uncheck everything but Download History. See https://support.mozilla.com/en-US/kb/Options+window+-+Privacy+panel#Use_custom_settings_for_history