Maintaining user profiles when upgrading from v24 to newest version 36.X - Enterprise

Question

Hi,
Im going to upgrade the Mozilla Firefox for about 500 users ish. The current version is 24.0 and we are upgrading to the newest version 36.0 something.
But the question is, how do I maintain all of the user settings when doing this upgrade? It is not an option to upgrade using the application itself. We have a centralized Config Mgr 2012 R2 solution. And I need to keep all of the user profiles with bookmarks, saved passwords, etc etc as it is today. The current version they are using have a few restrictions made with predefined and locked prefs in forms of automatic update, homepage, disabling the send data to Mozilla and so on, basically all of the standard enterprise configuration when you want to controll how the browser is for the users.
I've read a few articles on where to find spesific files, and what they are containting of information for the profile. But when doing a uninstall of the current version mozilla also removes whatever is stored in %appdata%\mozilla firefox\...profiles..
Is it even possible to "transfer" profiles for Version 24 to the newest version 36.something? Also, this needs automation, its not an option to manually restore each profile from "backup" for about 500 users. All profiles are unique.
Client computers are running Win 7 - 64bit OS.
Best Regards

Answer 1

To answer your question, when you update from 24 to 37 (the actual latest version) your profiles will migrate automatically, there should be no action needed on your part. We try to minimize profile breaking changes, so between versions 24 and 37 there is no need to do any special migration (that is only really a need when going from Firefox 3.6 or older to the latest version).
HOWEVER, since you are an enterprise and it looks like you only do upgrades every so often, I'd suggest you look into Firefox for Enterprises. https://www.mozilla.org/en-US/firefox/organizations/
This version only updates major versions once a year (so from Firefox 10 to 17, from 17 to 24, from 24 to 31, from 31 to 38) but it comes out with regular security updates every 6 weeks. This way you don't have to continually re-certify Firefox major versions every 6 weeks, and can simply let automatic updates push out security updates to your users every 6 weeks (With your current model your users are vulnerable to all security holes found until you push the next major update). Then, next year, you have a 12 week overlap between versions to test and make sure nothing breaks before you push to the next major version.
There is also a mailing list for you to get help and advice with specific Enterprise issues.
If you decide to go this route (which I would strongly advise) then I'd suggest you wait for a couple of weeks until Firefox 38 comes out, the next ESR version. Then you can certify and not have to worry about deployments until 45 next year!