What do the related prefs like when you check them on the about:config page? Are these prefs locked?

• signon.rememberSignons

You can sort the about:config page by status to show all locked prefs at the start (or end) of the about:config page.

You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue.

• http://kb.mozillazine.org/about:config

thank you for pointing it out, cor-el! in fact, it says locked and i can't find the option to unlock it.

Check if there is a mozilla.cfg file in the Firefox program folder to initialize (set/lock) preferences.

This requires a local-settings.js file in the "defaults/pref" folder where the channel-prefs.js file is located that specifies to use mozilla.cfg.

If there are .js files present in the "defaults\pref" folder apart from the channel-prefs.js file that sets app.update.channel then open this file in a plain texteditor like Notepad (Mac: TextEdit) and please post its content. Also please post the content of the mozilla.cfg file.

There shouldn't be a mozilla.cfg file present unless you've created it yourself or yopur IT department has added it to initialize some prefs.

• https://developer.mozilla.org/en-US/Firefox/Enterprise_deployment Enterprise_deployment_before_60

There is a mozzilla.cfg file in the program folder. As far as i know our IT guys or myself haven't created it (at least not on purpose). The content:

// try { lockPref("app.update.auto", false); lockPref("app.update.enabled", false); lockPref("app.update.mode", 0); lockPref("browser.download.useDownloadDir", false); lockPref("browser.rights.3.shown", true); lockPref("browser.search.update", false); lockPref("browser.shell.checkDefaultBrowser", false); lockPref("browser.startup.page", 1); defaultPref("browser.startup.homepage", "data:text/plain,browser.startup.homepage=http://mgs.marriott.com"); pref("browser.newtab.url","http://mgs.marriott.com") lockPref("browser.startup.homepage_override.mstone", "ignore"); lockPref("dom.allow_scripts_to_close_windows", true); lockPref("dom.disable_open_during_load", false); pref("dom.successive_dialog_time_limit", 0); lockPref("startup.homepage_override_url", "\"\""); lockPref("startup.homepage_welcome_url", "\"\""); pref("network.http.pipelining", true); pref("network.http.pipelining.maxrequests", 8); pref("network.http.pipelining.ssl", true); pref("network.http.proxy.pipelining", true); pref("network.proxy.autoconfig_url", "http://websense.marriott.com/proxy.pac");

pref("profile.allow_automigration", true); pref("profile.confirm_automigration", false); lockPref("security.warn_entering_secure", false); lockPref("signon.rememberSignons", false); lockPref("extensions.update.enabled", false); lockPref("toolkit.telemetry.enabled", false); lockPref("dom.url.getters_decode_hash", true); pref("toolkit.telemetry.prompted", 2); pref("toolkit.telemetry.rejected", true); } catch(e) { displayError("lockedPref", e); }

And there are only four .js files in the defaults/preferemce, nothing else (and i'm unable to open any of them):

all-walkme.js channel-prefs.js localsettings.js local-settings.js

If you can't remove the files in the defaults/pref folder apart from channel-prefs.js that is a legitimate file and mozilla.cfg in the main Firefox program folder then you should do a clean reinstall and remove the Firefox program folder. If you can't remove this folder then try to rename the current Firefox program folder.

Do a clean reinstall of the current Firefox release and delete the Firefox program folder before installing a fresh copy of the current Firefox release.

• download the Firefox installer and save the file to the desktop
  *https://www.mozilla.org/en-US/firefox/all/

If possible uninstall your current Firefox version to cleanup the Windows Registry and settings in security software.

• do NOT remove "personal data" When you uninstall the current Firefox version, because this will remove all profile folders and you lose personal data like bookmarks and passwords including data in profiles created by other Firefox versions

Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.

• (64-bit Firefox) "C:\Program Files\Mozilla Firefox\"
• (32-bit Firefox) "C:\Program Files (x86)\Mozilla Firefox\"

• it is important to delete the Firefox program folder to remove all the files and make sure there are no problems with files that were leftover after uninstalling
• http://kb.mozillazine.org/Uninstalling_Firefox

Your personal data like bookmarks is stored in the Firefox profile folder, so you won't lose personal data When you uninstall and reinstall or update Firefox, but make sure NOT to remove personal data When you uninstall Firefox as that will remove all Firefox profile folders and you lose your personal data.

If you keep having problems then you can create a new profile to test if your current profile is causing the problem.

• http://kb.mozillazine.org/Profile_folder_-_Firefox
• http://kb.mozillazine.org/Profile_backup

• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Clean_reinstall

Thank you so much for your time and help! Deleting those three files resolved the problem!