https://support.mozilla.org/en-US/kb/how-to-fix-preferences-wont-save

Note: Some software, like Advanced SystemCare with Surfing Protection, can protect files in the Firefox profile folder against changes. If you have such software then check the settings or uninstall this software.

It seems that the settings are being saved but because of my location (Mexico) it should only display pages in spanish. One other issue is that upon loading it goes to a download page for the latest version of Firefox. I have downloaded that but when I go to the download folder and click (and doubleclick) it fails to launch. Probably due to the fact I am running Vista which is probably no longer supported (understandably!) Interestingly, my Chrome browser, while also no longer supported, displays everything in English.

When you start Firefox, are you going straight into Google? Some sites can be switched to another language while others are more stubborn. This is the general "no country redirect" address for Google:

https://www.google.com/ncr

That will set a cookie which Google obeys until you clear cookies, then you'll need to visit that address to set it again or if you are on Google in another country, there may be an English or similar link toward the bottom of the page to get you back to the .com site.

Regarding downloading Firefox, Vista can run the Extended Support Release of Firefox 52, but not the current stable release, Firefox 58. So keep this page handy:

https://www.mozilla.org/en-US/firefox/organizations/all/

It seems I am getting closer but there are still bugs to getting Firefox to operating correctly. I have gone to the Mozilla site and downloaded the ESR of Firefox, completed the installation BUT when I click to open, it goes top opening page calling for the download (for the latest version?) and when I get to my homepage it remains in Spanish. I think I may need to uninstall everything (of Firefox) and then go to the Mozilla page and reinstall the Extended Support Release. Worth a try at least!

What is your home page? If it's a website, and not Firefox's built-in home page, the language of your home page may not have anything to do with your version of Firefox, but instead be determined by your connection (your ISP's IP address).

Many web pages have a language setting.

Stab in the dark, but would you take a look at this page and scroll down to 'Region Settings' :

https://www.google.com/preferences

Is that a problem with the user interface or a problem with web pages?

If the Firefox user interface (toolbars) is in the wrong language or if you want to change the current language then download Firefox in the language of your choice.

Firefox 52.6.0 ESR:

• https://www.mozilla.org/en-US/firefox/organizations/all/
• https://www.mozilla.org/en-US/firefox/52.6.0/releasenotes/
• https://www.mozilla.org/en-US/firefox/52.6.0/system-requirements/