When I go to the 3 horizontal bars in the top right, then click on the question mark and the select troubleshooting information, under User Agent its says Win64 which means it is the 64 bit edition. I see that the Firefox portable runs in dual mode of 32 bit and 64 bit but am lost on how this is possible. Not sure if this is the correct place to post this but this was the only topic I could find that was relevant to my issue. They do in an internal build I am testing. Both the PA.c Installer and PA.c Updater in the platform must support two downloads for the dual mode builds to be released. Dev and Nightly are online installers (downloading the latest builds from Mozilla on install) and would need to download both the 32-bit and 64-bit builds at install time. The only reason Firefox Portable Developer is 32-bit only and Nightly is split into 32-bit and 64-bit is because the Installer and Updater don't yet support two downloads for a single online/live installer. This is one reason why Mozilla doesn't automatically upgrade 32-bit users to the 64-bit version. Each release of Firefox Portable states: 'Firefox Portable is a dual-mode 32-bit and 64-bit app, ensuring Firefox runs as fast as possible on every PC.' Note, however, that 64-bit Firefox is still generally slower than 32-bit Firefox for the majority of websites and use cases. If you're using Firefox Portable stable channel on Windows 圆4, you're already using Firefox 圆4 you just didn't know it. It was worked this way since Dec 2015 when Firefox 圆4 went stable.

You'll be pleased to know that you're already using it Firefox Portable Stable includes both the 32-bit and 64-bit versions of Firefox within and will automatically use the appropriate version for the version of Windows it is running on.

Firefox 54 offline installer