Rated 5 out of 5 stars

For all of you need to don't have reset the user agent at firefox start up follow this:
Search prefs.js on your system and opening with worpad.
Add this to the last line:
user_pref("useragentswitcher.reset.onclose", false);
With that string you don't have reset on user agent after restarting.
And if after you doing that firefox is not start ( to me and my friends dosn't happens.
anyway you can repair that deleting that line:
general.useragent.override

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