Firefox, not Foxfire.

64-bit Windows can run 32-bit applications like Firefox just fine.

The earliest Release to maybe have Win64 Firefox is for Firefox 42.0 however it will not be listed on mozilla.org then.

Note that 64 bit Firefox versions on a 64 bit Windows platform will only support the Shockwave Flash plugin. If you need support for other plugins (Java or media players) then you need to stay with 32 bit Firefox versions.

It does not make any difference at the moment. Not a huge difference anyway. One difference to note though is if you use Firefox in a very heavy way with 100s of tabs and you notice high memory issues. The 64 bit version is able to use more memory (over 4GB) past the 32 bit limitation of 4GB. But if your Firefox is using 4GB of memory, you're already in big trouble. :P

If you don't use Firefox in that way, you won't notice much difference. Also 64 bit plugins for Java, Silverlight and a few others won't work because they're being blocked for security & stability reasons. And other plugins like VLC media player won't work with 64-bit Firefox because they haven't been whitelisted. So something to think about before switching. You can try out the 64-bit version here: https://www.mozilla.org/en-US/firefox/beta/all/

More info about the blocked plugins: http://www.ghacks.net/2015/07/30/mozilla-to-launch-64-bit-firefox-41-to-stable-channel/

Two articles about the theories/claims of 64-bit vs. 32-bit:

• http://www.i-programmer.info/news/86-browsers/7391-windows-chrome-64-bit-faster-better-more-stable.html
• http://www.pcworld.com/article/2892016/first-64-bit-firefox-build-released-promising-speed-boost-and-beefier-web-gaming.html

If you're not very computer savvy, just stick with 32 bit. 64 bit is better suited for advanced users & nerds at the moment. :)

Is it easy to switch back from 64 bit back down to 32 bit? Or is this a one shot deal?

My Firefox has been very slow yet, I believe because of high tab usage: 12-15, and Flash (that's my guess at least.)

Thanks very much, Jeremy

Hi jeremy3162

You can uninstall the 64 bit version and install the 32 bit version. If you possibly want to keep both then you can consider to do a custom install of the 32 bit version in the correct Firefox program folder for the 32 bit version and create a separate profile for the 32 bit version.

• (32 bit Windows) "C:\Program Files\Mozilla Firefox\"
• (64 bit Windows) "C:\Program Files (x86)\Mozilla Firefox\"

You can find the full version of the current Firefox release (44.0.2) in all languages and all operating systems here:

• https://www.mozilla.org/en-US/firefox/all/

Your personal data like bookmarks is stored in the Firefox profile folder, so you won't lose personal data when you uninstall and reinstall or update Firefox, but make sure NOT to remove personal data when you uninstall Firefox as that will remove all Firefox profile folders and you lose your personal data.

• http://kb.mozillazine.org/Profile_backup
• https://support.mozilla.org/kb/Backing+up+your+information