Use these steps to remove saved (form) data from a drop down list:

1. Click the (empty) input field on the web page to open the drop down list
2. Highlight an entry in the drop down list
3. Press the Delete key (on Mac: Shift+Delete) to remove it.

• http://kb.mozillazine.org/Deleting_autocomplete_entries

• Tools > Options > Privacy > Firefox will: "Use custom settings for history": "Remember search and form history"
• https://support.mozilla.org/kb/Form+autocomplete

Remove saved Password(s):

• Tools > Options > Security: Passwords: "Saved Passwords" > "Show Passwords"
• Tools > Options > Security: Passwords: [] "Remember passwords for sites"

The Library in the combined Bookmarks and History manager.

• Bookmarks > Show All Bookmarks
• https://support.mozilla.org/kb/how-do-i-use-bookmarks

Thank you cor-el, really appreciated. It worked on the computer at home. In the computer in the office I could follow your instructions: in fact I found another list of possibilities= 1) web search 2) Downloads 3) Add-ons 4) Error console 5) Page info 6) Start Private Browsing 7) Clear recent history 8) manage contents plu-ins. I tried all of them to understand what to do, but no success. Can you help, please. Thank you again.

Can you clarify if there is still data you failed to remove?

1) web search
Can you clarify what you mean with this?

• https://support.mozilla.org/kb/Search+bar

2) Downloads
Firefox manages downloads in the Downloads folder in the Library (History > Show All History)

• https://support.mozilla.org/kb/Downloads+window

• Downloads are treated as history items: clearing history removes included download items and vice verse.
• When downloads are in progress you see an animated download button on the Navigation Toolbar showing an estimate of the remaining time
• The Download button gets a green highlight once all download are finished to make you aware that new downloads are available.
• Pause and Resume can be found in the right-click context menu of an item.

You can display the new Download Manager in a tab by opening the about:downloads page and consider to open this page in a separate window.

3) Add-ons

• https://support.mozilla.org/kb/customize-firefox-with-add-ons-plugins-and-extensions
• https://support.mozilla.org/kb/extensions-add-features-to-firefox
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes
• https://support.mozilla.org/kb/Troubleshooting+plugins

• http://www.mozilla.org/plugincheck/

4) Error console

• https://developer.mozilla.org/en/Error_Console

5) Page info : Tools > Page Info (press F10 or tab Alt to get the menu bar)
6) Start Private Browsing : Firefox/File > New Private Window

• https://support.mozilla.org/kb/Private+Browsing

7) Clear recent history

• https://support.mozilla.org/kb/Clear+Recent+History

Note that clearing "Site Preferences" clears all exceptions for cookies, images, pop-up windows, software installation, and passwords.
Clearing cookies will remove all specified (selected) cookies including cookies that have an allow exception and cookies from plugins.

Hi co-rel, thank you for the replay. I could remove the saved passwords in the computer at home, but not in the computer at work: in fact I couldn't find the "lane" Tools>Options>Security>Passwords (saved passwords)>Show passwords as I found in the computer at home. So, I don't know what "lane" I have to follow to remove the passwords in the computer at work. The list of the possibilities when I click on Tools is: web-search, downloads, add-ons, error console, page info, start private browsing, clear recent history. Which one of them is the right one to find: options>security>passwords? Thank you again. Kind regards. gonefishinguk

Which Firefox version is installed on that computer?

• Help > About

Since you still have Start Private Browsing and Clear Recent History in Tools it would suggest that you have a quite old Firefox version (3.6.x ?) that still has these in the Tools menu and you should update to the latest Firefox version.

You can find the latest Firefox 20.0.x release in all languages and for all Operating Systems here:

• http://www.mozilla.org/en-US/firefox/all.html