I would not recommend trying to run both versions at the same time. Pick one or the other.

I run the ESR version which is very stable. Firefox ESR is the browser IBM uses on all of its corporate computers.

Hi Christine, when you posted your question, your Firefox indicated to the forum that it is version 42, not version 14. Could you clarify which version you have? The reason is that each update may make changes to your settings, and therefore it may not always work to use your existing settings folder with an older version of Firefox, or a much newer version of Firefox.

Either way, it's probably a good idea to make a backup of your settings (profile) folder before switching products. This article has tips on how to do that: Back up and restore information in Firefox profiles.

And then to switch to ESR (https://www.mozilla.org/firefox/organizations/), if you decide to do that, I suggest the following to avoid possibly mixed up program files:

(A) Download an installer for Firefox 38.6.0esr from https://www.mozilla.org/firefox/organizations/all/ to a convenient location. (Scroll down to your preferred language.)

(B) Exit out of Firefox (if applicable).

(C) Rename the program folder, either:

(64-bit Windows folder names)

C:\Program Files (x86)\Mozilla Firefox

to

C:\Program Files (x86)\FxOld

(32-bit Windows folder names)

C:\Program Files\Mozilla Firefox

to

C:\Program Files\FxOld

(D) Run the installer you downloaded in (A). It should automatically connect to your existing settings.

Note: Some plugins may exist only in that old folder. If something essential is missing, look in these folders:

• \FxOld\Plugins
• \FxOld\browser\plugins

It would probably be best to create a new profile for the ESR version and do a custom install of the ESR version and not start Firefox after the installation has finished.

You can do a custom installation and install each version in a different program folder and make sure that the "Launch Firefox now" checkbox doesn't have a tick.

• https://support.mozilla.com/kb/Custom+installation+of+Firefox+on+Windows
• https://www.mozilla.org/en-US/firefox/all/

Use the Profile Manager to create a new profile for this version, so make sure not to start Firefox after the installation has finished. The "profile" parameter is the name as seen in the Profile Manager and not the folder name on the hard drive. Create a desktop shortcut with -P "profile" appended to the target to launch each Firefox version with its own profile.

See:

• https://support.mozilla.org/kb/Managing+profiles

• http://kb.mozillazine.org/Creating_a_new_Firefox_profile_on_windows
• http://kb.mozillazine.org/Shortcut_to_a_specific_profile

Thank you. jscher2000 is right: my version is Firefox 42! If I save my bookmarks, uninstall version 42 and then download and install ESR version would I run in to any problems? Later I can import the bookmarks and install addons and plugins as required. I am not really interested in having two versions of Firefox.

Hi Christine, no need to uninstall. You can keep your existing profile folder for all that it contains, and use Firefox's profile manager to create a new profile as cor-el suggests, then restore your bookmarks from the first profile to the second one.

jscher2000 said

Hi Christine, no need to uninstall. You can keep your existing profile folder for all that it contains, and use Firefox's profile manager to create a new profile as cor-el suggests, then restore your bookmarks from the first profile to the second one.

Hello jscher2000,

In this case do I not end up with 2 Firefox browsers?

Regards, Christine

Christine said

jscher2000 said

Hi Christine, no need to uninstall. You can keep your existing profile folder for all that it contains, and use Firefox's profile manager to create a new profile as cor-el suggests, then restore your bookmarks from the first profile to the second one.

Hello jscher2000,

In this case do I not end up with 2 Firefox browsers?

Regards, Christine

You will still have the FxOld folder on your system and the old shortcut. So it's not as clean. However, I suggest it in case you need something from that FxOld folder.

Hello again jscher2000,

I just looked at what is stored in my Firefox Profile here:

https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data#w_what-information-is-stored-in-my-profile

I went through it all and decided I don't need to keep any of that information, except the bookmarks, which I can export and save. Does this justify my uninstalling Firefox 42 and starting off fresh with a completely new installation of the ESR.

Regards, Chistine

Hi Christine, if you're sure, then go for it.

By the way, Firefox has export and backup for bookmarks. Export is an older more universal format, while backup retains extra data such as tags. I suggest using both formats just in case.

• Export Firefox bookmarks to an HTML file to back up or transfer bookmarks
• Restore bookmarks from backup or move them to another computer

Hi Jscher2000,

That's great. Thank you for the advice about backup and export functions. I'll post here when I am done.

Regards, Christine