Rated 2 out of 5 stars

I'm running Firefox 25.0 on Windows XP SP3.

My purpose: to spoof my XP op system as Vista, because some websites may refuse to connect to XP after April 8, 2014. Some banks have already given notice that they're sunsetting XP after that date.

After installation of this add-on there was no icon or menu available to switch anything. I had to find it in the Customize box and drag it to a toolbar. I could find no instructions so had to google and try to figure it out on my own. Then I decided to venture trying to create a new useragent string, although there's no way to know for sure if I have the syntax right. It tested OK but wouldn't stick after restarting browser, so I had to put useragentswitcher.reset.onclose=false into about:config. That causes no apparent problems despite the warning, and I use java regularly. Also there is no general.useragent.override in my prefs.js file. And clicking on import useragent list does nothing, no action whatsoever.

So this add-on has insufficient, incorrect, and out-of-date details. That's not surprising because the build date is January 2011, more than 3 years ago. Please update, and if possible make it available for SeaMonkey as well as Firefox! I'm quitting Firefox soon, 25.0 will be my final version, no Australis junk for me.

Bottomline, it seems to work, but I wouldn't bet on it working tomorrow. So on second thought, I'll probably only use this with a portable browser, not my primary installed browser. That will make it a sort of backup when my regular browser fails. I keep portable copies of chrome, opera, etc just for that purpose.