Mozilla has been working on a 64-bit version for a while now, but it is only for testing and not yet released.

I see what you're quoting on the system requirements page for Firefox beta 42.0: https://www.mozilla.org/firefox/42.0beta/system-requirements/

But I don't know whether that means it won't actually run on Vista and 7, or whether it has known bugs on Vista and 7 that make it an unattractive proposition to run it on those OSes...

Why is it important to you that you run a 64-bit version of Firefox instead of the regular 32-bit release? People say the performance is better if you shed the code that makes it backwards compatible with 32-bit systems, and you also can use lots more RAM. But I'm not sure how much that affects day-to-day use compared with changing from a spinning hard drive to an SSD or buying more RAM (which you probably would need if you start using multiple 64-bit applications).

If you want to try installing beta, it's available here: https://www.mozilla.org/firefox/beta/all/ (scroll down to your preferred language)

Oh, I see, you already tried that: https://support.mozilla.org/questions/1070035#answer-785584

This harming your PC message must be something generated by IE9 or your security software. Websites normally wouldn't code that into their download links!

jscher2000 You said maybe my security might be the reason I can download the 64 bit web browser of firefox beta. I use avg + Windows Defender is that something AVG might do?

What I would do is search Google for the exact error message and see whether that leads to a specific explanation.

As far as the speed issue, when I used 64 bit palemoon, I noticed a difference in speed within the first minute of usage. Palemoon just could not be the default browser and that stunk.

Why can't Pale Moon be the default browser? Maybe you installed the "portable" version instead of the regular version. As far as I know, the regular version can be set as the default browser.

When i used firefox 32 bit, latest version my pc seemed to freeze up alot. I then tried chrome and that was a total nightmare plus total malware

I can't help with Chrome, but if you want to test Firefox further, I'd suggest trying to rule out Flash as a culprit for freezes. I'll add a separate reply for that.

For "not responding" problems, to minimize potential issues with Flash, I suggest two things:

(1) To avoid unnecessary pain on sites where Flash is not actually essential, try setting Flash to Click-to-Play ("Ask to Activate"). This will delay Flash from starting on a page until you approve it.

To set "Ask to Activate", open the Add-ons page using either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Plugins. Look for "Shockwave Flash" and change "Always Activate" to "Ask to Activate".

With this setting, when you visit a site that wants to use Flash, you should see a notification icon in the address bar and usually (but not always) one of the following: a link in a black rectangle in the page or an infobar sliding down between the toolbar area and the page.

The plugin notification icon in the address bar typically looks like a small, dark gray Lego block. (If it's red, Flash needs updating.)

The delay in activating Flash can help distinguish between problems caused on initial page load, styling, and script activation vs. Flash.

If you see a good reason to use Flash, and the site looks trustworthy, you can go ahead and click the notification icon in the address bar to allow Flash. You can trust the site for the time being or permanently.

But some pages use Flash only for tracking or playing ads, so if you don't see an immediate need for Flash, feel free to ignore the notification! It will just sit there in case you want to use it later.

(2) A common cause of unresponsive script errors on Windows Vista and higher is the protected mode feature of the Flash player plugin. That feature has security benefits, but seems to have serious compatibility issues on some systems. You can disable it using the Add-ons page. Either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Plugins. On the right side, find "Shockwave Flash" and click the More link. Then uncheck the box for "Enable Adobe Flash protected mode" and try that for a day to see whether it helps.

Ragnuts said

I have a very nice computer. It is a 64 bit windows vista. I been scouting all over for a version of firefox to support windows vista 64 bit. I found one that said it did. It was 4.0 firefox and it was 64 bit and was for windows 7 and vista. When I went to download it, a pop up came up stating that it only come in the 32 bit version. That is not what was advertised. I would like to know if Mozillz is ever going to build a 64 bit web browser for vista 64 bit? There are still a lot of people out there still using xp and a lot still using vista.

Firefox 4.0 was the first Release to have 64-bit bit Releases for Mac OSX and Linux from Mozilla as there has been only 32-bit for Windows since. Making 64-bit Firefox Releases for Mac OSX and Linux was both easier and needed while it was not needed for 64-bit Windows in order to use Firefox.

The Win64-bit builds of Firefox (since 36.0 ?) on the Beta < Aurora (developer edition) < Night channels have needed 64-bit Windows 7, 8 or 10 in order for Win64 Firefox to run.

The 64-bit WinXP, Vista and servers cannot run Win64 Firefox builds. WinXP is EOL since April 2014 and Vista is EOL in April 2017. The market of 64-bit Vista users is rather small to try and make Win64 builds for them as this Steam survey http://store.steampowered.com/hwsurvey can show (click on OS on page).

There has been various hurdles and priorities all this time in trying to get Win64 Firefox to Release state. Just building Win64 builds is not enough to do so.

The earliest Firefox Release to have WIn64 may be Firefox 42.0

'I appreciate all of your feedback and help. I have to admit some of what your advice is over my head. I thought I knew quite a lot about pc's until you guys started giving me advice. I just don't know what to do. The advice you gave me about the flash,, I don't have a clue what your talking about. You on the other hand been very kind and I know your trying to help me. I might have to take it in to see if I can't get a professional to install it. I don't want to do that, but I just don't know enough of the computer slang etc. etc.etc. Thank You for your support'jscher2000 said

Oh, I see, you already tried that: https://support.mozilla.org/questions/1070035#answer-785584 This harming your PC message must be something generated by IE9 or your security software. Websites normally wouldn't code that into their download links!