If you want to change Firefox language you must first download it because if want to change it directly it will have no effect. Currently this is only working way to change Mozilla Firefox Language if you don’t want to uninstall and then install again Firefox.
Downloading and installing Mozilla Language Pack:
So, go here https://addons.mozilla.org/ro/firefox/language-tools/ and download your language by clicking “Install Language Pack”
Click on “Add to Firefox” Button:
And then click on Install Now button as you can see:
Then restart your Firefox!
How to Change Firefox Language:
1. Go to Top Left Corner >> Firefox >> Options >> Options:
Go on Tab Content and then click on Choose… .
Click on Installed language then move it up on first position.
That is not all, if you press ok and restart your Firefox the language will be the same, you have to follow the next steps to complete changing.
Go to address Bar, insert this
about:config then and hit enter.
In the search filed of new windows insert this code
general.useragent.locale and press enter.
And now you see and insert box that you have to modify value from [ ] of language that you’ve installed:
If you don’t want to reinstall Mozilla Firefox this is only working way to change language on Mozilla Firefox.
Please comment and let me know if it worked normal.