Windows 7 – Command-Line to Remove All Saved Passwords in Credential Manager

OK so here is another answer I think is more convenient that the Javascript one.

First go to your Firefox components folder, by default in my case it's "C:\Program Files\Mozilla Firefox\components"

Now open the file nsLoginManager.js

Go to the function at around line 804 (varies with version of Firefox), that reads:

/*
 * _isAutoCompleteDisabled
 *
 * Returns true if the page requests autocomplete be disabled for the
 * specified form input.
 */
_isAutocompleteDisabled :  function (element) {
    if (element && element.hasAttribute("autocomplete") &&
        element.getAttribute("autocomplete").toLowerCase() == "off")
        return true;

    return false;
},

Now comment out the first 3 lines, so it ends up like this:

/*
 * _isAutoCompleteDisabled
 *
 * Returns true if the page requests autocomplete be disabled for the
 * specified form input.
 */
_isAutocompleteDisabled :  function (element) {
    /*if (element && element.hasAttribute("autocomplete") &&
        element.getAttribute("autocomplete").toLowerCase() == "off")
        return true;*/

    return false;
},

Save it, restart Firefox and you should be good to go...

For completeness, you can manage credentials at the command line or in batch script with cmdkey.exe (located in %windir%\system32).

For example, to add (or update) the credentials on server.domain.tld:

cmdkey.exe /add:server.domain.tld /user:username /pass:password

or for the entire domain:

cmdkey.exe /add:*.domain.tld /user:username /pass:password

/user can also take domain\username or username@domain

Instead of opening Windows Vault you could run a simple batch script that would prompt you for your new password:

set /p pw=Enter your new password:
cmdkey.exe /add:*companydomain.tld /user:myusername /pass:%pw%