You might have noticed that I spend most of my resources around configuring Firefox and not around deploying Firefox. There are a couple reasons for that:

1. There really isn’t a "one size fits all" solution for Firefox deployment because there are so many products that can be used to deploy software within different organizations.
2. Most discussions around deployment devolve into a "I wish Mozilla would do a Firefox MSI" discussion.

That being said, there are some things I can recommend around deploying Firefox on Windows.

If you want to modify the Firefox installer, I’ve done a few posts on this in the past:

• Integrating Add-ons into Firefox
• Customizing the Firefox Installer on Windows

If you need to integrate add-ons into that install, I've posted about that as well:

• Integrating Add-ons into Firefox
• Understanding Add-on Scopes

You could also consider asking on the Enterprise Working Group mailing list. There's probably someone that's already figured it out for your software deployment solution.

If you really need an MSI, check out FrontMotion. They've been doing MSI work for quite a while.

And if you really want Firefox to have an official MSI, consider working on bug 598647. That's where an MSI implementation got started but never finished.

http://mike.kaply.com/2015/01/27/what-about-firefox-deployment/