Managing Firefox in AD Environment

You can't control firefox or chrome with group policy, in the full sense of policy control. For the full control, the product itself must be group-policy aware. What this means is that whenever it reads a setting from the registry, it first has to try to read the same setting from the part of the registry that is controlled by group policy. For example, if Firefox is going to decide whether to accept a cookie or not. it should read something like software/mozilla/firefox/allowcookies, but first it has to try software/policies/mozilla/firefox/allowcookies. Group policy (or more specifically, winlogon.exe) maintains those parts of the registry. If the user goes and changes the value in the policy part (by going to application settings, or directly by regedit), in seconds winlogon will overwrite it with the value from the policy, so practically in no time the browser would be able to use wrong settings. That's how it was already in IE6, and then in later versions those settings that are controlled by GP are even dimmed out, so the user can't even change them.  Another part of the equation is that the browser has to read those settings from the registry on every operation - rather tnan do it once when it just has been launched, and then remember. That's exactly what makes it a policy, and as you can see it depends on whether the browser is programmed with policy in mind. Neither firefox, nor chrome do that. Those fake policies that are offered basically translate the settings into javascript-based settings, and give them to firefox. But then nothing prevents the user from changing them in the next moment. Of course, not many users will know to do that, so probably in 90% it would be sufficient, but technically, it's not how group policy is supposed to work.

Which means: if you really need policies, use IE, as it's the only browser that is fully compliant with them.

That said, I've found that it's better to focus security efforts on the proxy server and block bad websites, rather than control everyone's browser.

Yes all of that I understand and was hoping wouldn't be the case. I mean in this company we were flexible enough to allow these other browser in the first place so we aren't super controlling or haven't been in the past.

The xpi extension I have actually locks the user from changing the settings but it not manageable as if there is an update I need to push out, it would have to override this.

I know you can set the homepage in the registry but again, if they change it, the "policy" won't switch back until they reboot which people probably don't do often.

It isnt really anything I can use in our environment but seems to have been the best alternative.