You posted here with the 64-bit version of Firefox 43.

While it is quite splendid that you are able to tell that the OP has indeed posed his question with his 64 bit version of Firefox, the fact that he even has to ask points out a flaw in Firefox. One that should be really easy for you guys to fix.

PEOPLE NEED FEEDBACK. They need that crumb of comfort that tells them that what they have done has succeeded - without having to post questions on this board.

When I looked at installing 64 bit Firefox, I noticed that the download filename for the Windows 32bit and 64bit versions are EXACTLY THE SAME. And then the install procedure does not then mention 64 bit at all.

There is a slight clue that once installed there is a Mozilla Firefox directory in Program Files, but I note that the old Firefox folder in Program Files (x86) has not been tidied up. Do I really have to examine the properties of my Firefox shortcut to figure out which folder it's going to run it from? That's not really feedback is it? Because once launched how do I know that it hasn't decided for me which version to run? Feedback. Feedback. Feedback. The program should be telling me, giving me some indication of what it's done.

So, some suggestions:

May I suggest that you modify the install procedure to mention 64 bit somewhere, so the user has some comfort as to what they are about to install on their system.

May I also suggest that you modify Help > About Firefox to display which version (32 or 64 bit) the user is running? You might not think it's important, but for many end users, it is. And it will avoid you having to answer such questions here in Mozilla Support.

Otherwise, keep up the good work. I love Firefox and Thunderbird.