In contrast to all other programs discussed here, there are no MSI-files available for Firefox from Mozilla. Mozilla offers only an installer of kind setup.exe based on NSIS (Nullsoft Scriptable Install System). This installer does not internally base on MSI, it is not possible to extract an MSI-file from it.
Instead I provide some download links and two descriptions how you can easily create MSI-files for Firefox and Thunderbird yourself. In both cases the resulting MSI-files will install all files, set the required registry keys, and add a few config files.
Using AdvancedInstaller works great, but now I'm moving to WiX, because it's easier to fully automate this.
I plan to update the WiX description for version 24 shortly (different directory structure, new 'browser' subdirectory). Right now I'm struggling to create new clean registry files, and check if they should differ for XP, 7-32, 7-64. RegFromApp is a great tool to get cleaner registry files, but even they need a bit cleanup. And in Windows 7 some steps are more difficult than in XP, because it's not compatible, and UAC always get's in the way.
Create Firefox.msi with WiX
Slightly more difficult to set up than AdvancedInstaller, but requires a lot less clicks on each use. Should also be more resiliant against changes in new Firefox versions, because it extracts everything from the firefox-setup.exe file.
Copy the program directory to a server and let the clients run it from there
This works, but has some disadvantages:
somehow script the installer.exe
install with command-line option -ms, use helper.exe to set it as default, and for for uninstall.
download MSI-files from Frontmotion
They offer some free service, and also payed support contracts, that can include individual configuration changes according to your specific needs.
I'm reluctant to use any 3rd party offerings because
use the package from Bespoke I/O
Used to be similar offer like the one from Frontmotion. Now it's free, but there's no support any more.
"BeSDS is a Firefox & Thunderbird customization and deployment tool, derived from Mozilla's BYOB project."
Use the "setup.exe wrapped in MSI" trick using custom-actions of windows-installer.
It seems that the program "Windows Installer Wrapper Wizard" isn't available any more. Alternatively XML-files for WiX are available that also use the wrapper trick, but some of them even don't include an uninstall feature. I have seen one that does, if I can find it again I'll try to show it here.
Use "Exe-To-MSI" converter
This records and later plays back the keystrokes that are needed to install the setup.exe
Interesting idea, haven't tried this one yet. It seems the latest version isn't free any more.
Use imaging tools like WinInstall LE.
Disadvantage: MSI-files created with such tools are unreliable.
wait until Mozilla offers MSI-files
There are discussions inside Mozilla to provide MSI files (e.g. in bug reports 598647 and 231062), but the files are not yet available for download, and it's unclear how long that will take. The discussions are ongoing since many years.