Firefox for Windows finally has an official, stable 64-bit buildToday, with the release of Firefox 43, almost a decade after the idea was first mooted, there is finally an official 64-bit build of Firefox for Windows. To download it, you'll have to head over to the Firefox website and explicitly grab a 64-bit installer; if you just do an in-place upgrade you'll just get the normal 32-bit flavour. 64-bit Firefox for Windows is mostly identical to 32-bit Firefox
