This is the error window

Your error report lists your browser version as Firefox 28.0. Did you try updating from this version or did you run an installer?

The first thing to try is Safe Mode in Firefox: https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode#w_how-to-start-firefox-in-safe-mode. If Firefox starts in Safe Mode, an extension, theme, or setting may be causing the error.

If Safe Mode won't start either, it's time to reinstall Firefox. Back up your profile so you won't lose data, https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles, and then fetch a fresh installer from the official page: https://www.mozilla.org/en-US/firefox/all/. Install on top of the old Firefox folder - no uninstall required. Then try again.

If you still can't start Firefox, you may have to root out the installation altogether, then reinstall without any previous files.

Just as background infomation: what antivirus solution are you using? Is there other software running that can stop other software from executing?

Well said.

Phoxuponyou said

Your error report lists your browser version as Firefox 28.0. Did you try updating from this version or did you run an installer? The first thing to try is Safe Mode in Firefox: https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode#w_how-to-start-firefox-in-safe-mode. If Firefox starts in Safe Mode, an extension, theme, or setting may be causing the error. If Safe Mode won't start either, it's time to reinstall Firefox. Back up your profile so you won't lose data, https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles, and then fetch a fresh installer from the official page: https://www.mozilla.org/en-US/firefox/all/. Install on top of the old Firefox folder - no uninstall required. Then try again. If you still can't start Firefox, you may have to root out the installation altogether, then reinstall without any previous files. Just as background infomation: what antivirus solution are you using? Is there other software running that can stop other software from executing?

Ooops, That's why I can only install an older version...

I tried what you mentioned before but no help, I did not install any antivirus program, could I find any error report or log that may help to find out the solution? I may upload it here, Thanks.

Okay, so Firefox will not start even in Safe Mode. Did you try the same desktop shortcut as before after reinstalling Firefox? Or did you use the new shortcut in Windows' Start Menu generated by the installer? If you tried from the desktop, please try the Start Menu shortcut instead - the desktop shortcut is not named like the standard Firefox shortcut.

Speaking of, Mozilla does not have a release version in 64-bit. Is this a third-party release like Waterfox or a Nightly testing build? -- If you want to access Firefox error reports but can't start Firefox, see here for instructions: https://support.mozilla.org/en-US/kb/mozillacrashreporter#w_viewing-reports-outside-of-firefox.

Windows logs will contain some information as well (right-click My Computer, select Manage, then use Event Viewer), but it may not be useful and will probably protract the troubleshooting process. -- Uploading reports would be a good next step.

If you want to take action, I would make sure you are protected (as you haven't installed an antivirus suite) and malware-free.

• Go to Control Panel\System and Security\Action Center (you can enter that directly into Windows Explorer's address bar) and check that you have a firewall and antivirus and malware protection On under Security.
• Run the scanners suggested in this article: https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware#w_how-do-i-get-rid-of-malware/. (yes, the lot of them, as just one may miss something)
• IF malware is found, remove it and scan and clean until you're secure.
• Once nothing is found by the scanners and you have protection On, reboot the machine to verify everything is still working.
• Check Windows Update for any Windows updates. Malware and software errors can cause updates not to install correctly, which will subsequently leave a system vulnerable and possibly prevent programs from running correctly.
• Check for driver updates for your graphics chip. This may sound redundant, but stranger things have happened than bad video drivers crashing browsers.
• Once your machine is protected, secured, and up to date, try reinstalling Firefox again.

If no malware is found or Firefox still won't reinstall and launch after the above, it's time to uproot the old, possibly corrupt Firefox.

• Make sure you have a backup of your current profile, use the instructions in the previous reply.
• Use the instructions at https://support.mozilla.org/en-US/kb/uninstall-firefox-from-your-computer to remove Firefox AND its files. Then remove the profiles (again, make sure you have backups).
• Download a fresh installer from https://www.mozilla.org/en-US/firefox/all/ (in case you had an infection and the previous download was corrupted) and install Firefox.

That is all I can come up with until more information is available.

Start your Computer in safe mode with networking. Then start Firefox. Try Safe web sites. Is the problem still there?

Starting The Computer In Safe Mode;
Free Online Encyclopedia

Phoxuponyou said

Okay, so Firefox will not start even in Safe Mode. Did you try the same desktop shortcut as before after reinstalling Firefox? Or did you use the new shortcut in Windows' Start Menu generated by the installer? If you tried from the desktop, please try the Start Menu shortcut instead - the desktop shortcut is not named like the standard Firefox shortcut. Speaking of, Mozilla does not have a release version in 64-bit. Is this a third-party release like Waterfox or a Nightly testing build? -- If you want to access Firefox error reports but can't start Firefox, see here for instructions: https://support.mozilla.org/en-US/kb/mozillacrashreporter#w_viewing-reports-outside-of-firefox. Windows logs will contain some information as well (right-click My Computer, select Manage, then use Event Viewer), but it may not be useful and will probably protract the troubleshooting process. -- Uploading reports would be a good next step. If you want to take action, I would make sure you are protected (as you haven't installed an antivirus suite) and malware-free.

• Go to Control Panel\System and Security\Action Center (you can enter that directly into Windows Explorer's address bar) and check that you have a firewall and antivirus and malware protection On under Security.
• Run the scanners suggested in this article: https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware#w_how-do-i-get-rid-of-malware/. (yes, the lot of them, as just one may miss something)
• IF malware is found, remove it and scan and clean until you're secure.
• Once nothing is found by the scanners and you have protection On, reboot the machine to verify everything is still working.
• Check Windows Update for any Windows updates. Malware and software errors can cause updates not to install correctly, which will subsequently leave a system vulnerable and possibly prevent programs from running correctly.
• Check for driver updates for your graphics chip. This may sound redundant, but stranger things have happened than bad video drivers crashing browsers.
• Once your machine is protected, secured, and up to date, try reinstalling Firefox again.

If no malware is found or Firefox still won't reinstall and launch after the above, it's time to uproot the old, possibly corrupt Firefox.

• Make sure you have a backup of your current profile, use the instructions in the previous reply.
• Use the instructions at https://support.mozilla.org/en-US/kb/uninstall-firefox-from-your-computer to remove Firefox AND its files. Then remove the profiles (again, make sure you have backups).
• Download a fresh installer from https://www.mozilla.org/en-US/firefox/all/ (in case you had an infection and the previous download was corrupted) and install Firefox.

That is all I can come up with until more information is available.

Here is the link of official FF42.0 x64: https://ftp.mozilla.org/pub/firefox/releases/42.0/win64/en-US/Firefox%20Setup%2042.0.exe

The error window appeared even I run C:\Program Files\Mozilla Firefox\firefox.exe directly, weird! I am sure my machine has no malware because I just formatted it and make it clean. I just wonder if the x64 release of FF does not support my CPU because it works seamlessly on my laptop which it runs with a Sandy Bridge CPU...

Anybody following this issue!?

What Firefox version are you trying to fix?

Are you using the current release (42) or are you using an older version?

You can try to do a custom install of Firefox 42 in a separate program folder if you have reverted to an older release. You need to use the Profile Manager to create a new profile folder.

• http://kb.mozillazine.org/Profile_Manager

Boot the computer in Windows Safe Mode with network support (press F8 on the boot screen) to see if that helps.

• http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/
• http://www.7tutorials.com/4-ways-boot-safe-mode-windows-10

Do a malware check with several malware scanning programs on the Windows computer.

• https://support.mozilla.org/kb/troubleshoot-firefox-issues-caused-malware

Please scan with all programs because each program detects different malware. All these programs have free versions.

Make sure that you update each program to get the latest version of their databases before doing a scan.

• Malwarebytes' Anti-Malware:
  http://www.malwarebytes.org/mbam.php
• AdwCleaner:
  http://www.bleepingcomputer.com/download/adwcleaner/
  http://www.softpedia.com/get/Antivirus/Removal-Tools/AdwCleaner.shtml
• SuperAntispyware:
  http://www.superantispyware.com/
• Microsoft Safety Scanner:
  http://www.microsoft.com/security/scanner/en-us/default.aspx
• Windows Defender:
  http://windows.microsoft.com/en-us/windows/using-defender
• Spybot Search & Destroy:
  http://www.safer-networking.org/en/index.html
• Kasperky Free Security Scan:
  http://www.kaspersky.com/security-scan

You can also do a check for a rootkit infection with TDSSKiller.

• Anti-rootkit utility TDSSKiller:
  http://support.kaspersky.com/5350?el=88446

See also:

• "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked

There's probably a reason for why the 64-bit version is still hidden on the FTP and not released on the public page. If this is hardware/CPU incompatibility, then there's nothing more I can do here - it'll be up to reporting and Bugzilla.

Good idea testing on different hardware!

Just as a side note at this point: this sort of behaviour is typical of overzealous AV (which may or may not report the action taken) or malware preventing the launch of a program they've deemed a threat. Fresh systems are prime real estate for infections if they lack updates; Windows 7 at least has the Firewall+Defender combo going for it (now very long in the tooth if installed as original or SP1), XP was hopeless. Malware comes up time and again here.

PS. If you absolutely want a 64-bit Gecko browser and can't get Firefox to run, Cyberfox has an AMD-optimised release in 42.x/64-bit. Could try and see if that will launch.

To pursue the hardware angle further: are you using the CPU-integrated GPU? Do you use multiple monitors? Do you have the latest drivers for chipset (which chipset) and GPU (what version)?

The multiple monitor angle came up on Bugzilla, ditto the GPU. I assumed you had installed the latest stuff when you formatted and reinstalled Windows, but it's something that needs to be verified. Safe Mode should have sidestepped hardware acceleration, but that may not be all since we're talking about the new 64-bit release here.

Phoxuponyou said

To pursue the hardware angle further: are you using the CPU-integrated GPU? Do you use multiple monitors? Do you have the latest drivers for chipset (which chipset) and GPU (what version)? The multiple monitor angle came up on Bugzilla, ditto the GPU. I assumed you had installed the latest stuff when you formatted and reinstalled Windows, but it's something that needs to be verified. Safe Mode should have sidestepped hardware acceleration, but that may not be all since we're talking about the new 64-bit release here.

A10-7700K is an APU, you may google it for more information. I dont use multiple monitors and I have the latest drivers for all hardwares installed.

Here is my machine's config:

I know what it is, no need to be patronising. Hence why I was asking about the integrated GPU.

If you have the latest drivers and software updates and there are no alternative ones available, that's the end of that road then. The chipset should be mature, too.

Did you try Cyberfox?

In case it helps, a similar issue was reported in the mozilla.support.firefox newsgroup. The problem turned out to be Comodo Internet Security version 5. See this thread:

https://groups.google.com/forum/m/#!topic/mozilla.support.firefox/G6YHZzZpk6Q FF 42 64bit crashes at startup no matter what (32bit runs fine) (quote) So I decided to install the 64 bit version of Firefox <snip> and to my surprise it doesn't work. It crashes immediately with the "Firefox has stopped working" message. I tried to run it in safe mode by adding -safe-mode to the shortcut, I tried removing my profile, and I even tried uninstalling everything from mozilla, and instaling the 64 bit version again, I tried disabling my antivirus and firewall, I even tried installing the non-EME-free version, but it still just crashes as soon as I double click the shortcut.

(quote) I discovered the problem finally. FF 64 bit crashes when Comodo Internet Security version 5 is installed. Even if it is disabled.

Phoxuponyou said

I know what it is, no need to be patronising. Hence why I was asking about the integrated GPU. If you have the latest drivers and software updates and there are no alternative ones available, that's the end of that road then. The chipset should be mature, too. Did you try Cyberfox?

Thanks for your replies.

I did not try Cyberfox because I dont trust 3rd party stability. I just wanna know do mozilla notice about this uncertain incompatibility issue after I just raise it up here? I did not find any email contact way of mozilla.

AliceWyman said

In case it helps, a similar issue was reported in the mozilla.support.firefox newsgroup. The problem turned out to be Comodo Internet Security version 5. See this thread: https://groups.google.com/forum/m/#!topic/mozilla.support.firefox/G6YHZzZpk6Q FF 42 64bit crashes at startup no matter what (32bit runs fine) (quote) So I decided to install the 64 bit version of Firefox <snip> and to my surprise it doesn't work. It crashes immediately with the "Firefox has stopped working" message. I tried to run it in safe mode by adding -safe-mode to the shortcut, I tried removing my profile, and I even tried uninstalling everything from mozilla, and instaling the 64 bit version again, I tried disabling my antivirus and firewall, I even tried installing the non-EME-free version, but it still just crashes as soon as I double click the shortcut. (quote) I discovered the problem finally. FF 64 bit crashes when Comodo Internet Security version 5 is installed. Even if it is disabled.

Ooops...you seem to have just hit the target

Is there any alternative since I found COMODO firewall perfect among different firewall products...

tkrojam said

Thanks for your replies. I did not try Cyberfox because I dont trust 3rd party stability. I just wanna know do mozilla notice about this uncertain incompatibility issue after I just raise it up here? I did not find any email contact way of mozilla.

You're welcome. I see it turns out it wasn't malware but the protection at fault; sometimes it's hard to tell the two apart as they take over control from the user.

For future reference, Firefox has a feedback page at https://input.mozilla.org/en-GB/feedback/. You can leave your email to be contacted, but the support forum is definitely a good way to get immediate help for actual issues.

From what I have heard and seen in use, ESET works well in general and gets along with Firefox - dunno about 64-bit yet though. I personally use Bitdefender for myself and my business. They've had stupid on-desktop advertising in the past and a wonky SSL scanning implementation, but they have improved since and are open to user feedback.

Off the top of my head, the list of security software to approach cautiosly (especially regarding Firefox) includes Avast, AVG, ZoneAlarm, Norton, Kaspersky, McAfee, and Websense. All have caused issues and/or controversy.

tkrojam said

Ooops...you seem to have just hit the target Is there any alternative since I found COMODO firewall perfect among different firewall products...

Can you update Comodo to a newer version that might not have the issue? You could also visit Comodo Support to see if there's a workaround, since there might be a setting in their program you can turn off or adjust.

As for alternatives, I simply use Windows Firewall and Microsoft Security Essentials on my Windows 7 64-bit system. Een though MSE isn't highly rated I'm satisfied with it.