When I went through this with support 1 year ago, this was the solution that was offered.

https://support.mozilla.org/en-US/questions/965409?esab=a&s=&r=1&as=s

The hangups/not responding windows occur every 2 mins and last for 30 seconds - making the browser just about unusable.

Even a youtube video halts in the middle of playing for 30 seconds...

Did you check your security software (firewall, anti-virus)?

It is possible that your security software (firewall, anti-virus) blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.

Remove all rules for Firefox and the plugin-container from the permissions list in the firewall and let your firewall ask again for permission to get full, unrestricted, access to internet for Firefox and the plugin-container process and the updater process.

See:

• https://support.mozilla.org/kb/Server+not+found
• https://support.mozilla.org/kb/Firewalls

• https://support.mozilla.org/kb/fix-problems-connecting-websites-after-updating

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

• http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/

>It is possible that your security software (firewall, anti-virus) blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.

No, not possible. The computer has been running the same AV product and Fw settings (to block inbound connections to programs not specifically allowed only) for 3.5 years. Until today, aside from the weekly hangs that require task kill, there has been no other abnormal behavior on the browser.

It is still worth a try to make sure that it isn't an issue with your security software.

Do a clean reinstall and delete the Firefox program before (re)installing a fresh copy of the current Firefox release.

• Download the full Firefox installer and save the file to the desktop
  https://www.mozilla.org/en-US/firefox/all.html

If possible uninstall your current Firefox version to cleanup the Windows registry and settings in security software.

• Do NOT remove "personal data" when you uninstall your current Firefox version, because this will remove all profile folders and you lose personal data like bookmarks and passwords including data in profiles created by other Firefox versions.

Remove the Firefox program before installing that newly downloaded copy of the Firefox installer.

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

• It is important to delete the Firefox program to remove all the files and make sure that there are no problems with files that were leftover after uninstalling.
• http://kb.mozillazine.org/Uninstalling_Firefox

Your bookmarks and other personal data are stored in the Firefox profile folder and won't be affected by an uninstall and (re)install, but make sure that "remove personal data" is NOT selected when you uninstall Firefox.

If you keep having problems then also create a new profile.

• http://kb.mozillazine.org/Profile_folder_-_Firefox
• http://kb.mozillazine.org/Profile_backup

• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Clean_reinstall

I would really like to have something a little more definitive than this might fix it - especially considering how long this problem has existed. I did the new profile and spent several hours on this effort a year ago. If there is not something that is more likely, I will probably just uninstall and leave it that way. I am running this on a 64 bit system, are there no 64 bit versions of FF for windows even after this length of time?

Unfortunately, while Firefox collects detailed data on crashes, it does not accumulate detailed data on hangs. So some guesswork is required.

Did this newly aggravated problem coincide with any software changes, such as a Firefox update, a Windows update, security software update, or any add-on updates?

No, there had been no changes on the workstation prior to this problem (the 30 second hangs every 2 mins).

I never saw an answer to the question I had about 64 bit versions under win7. Is there nothing but 32 bit versions?

I assume at some point you tested in Firefox's Safe Mode to see whether the problem is equally severe. If not, you can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• (menu bar) Help > Restart with Add-ons Disabled

Not all add-ons are disabled: Flash and other plugins still run

After Firefox shuts down, a small dialog should appear. Click "Start in Safe Mode" (not Reset).

Any difference?

Flash troubleshooting

As the most commonly used plugin and a known cause of hangs on some systems, you may want to try disabling the protected mode feature of the plugin. This involves creating or editing a settings file. The following pages/posts provide different ways to do that:

• Adobe support article under the heading "Last Resort": Adobe Forums: How do I troubleshoot Flash Player's protected mode for Firefox?

• Manual steps: https://support.mozilla.org/questions/968190?page=5#answer-509209

• Batch file to automate the manual steps: https://support.mozilla.org/questions/982093#answer-518078

Flash needs to completely unload from memory (exiting and starting Firefox up again might help) before this takes effect.

Regarding 64-bit

There is not a 64-bit "release" version of Firefox for Windows. There is a 64-bit bleeding edge test version ("Nightly") that I definitely do not recommend for normal daily use.

On the plus side, 64-bit programs can use much more memory. On the minus side, many plugins are not available for 64-bit builds of Firefox.

Some other developers have taken parts of the Firefox code base and created their own 64-bit builds, Waterfox and Pale Moon. I haven't tried those myself.

I performed a reinstall and the 30 second hangs every 2 mins are gone. Unsure about the original hang problem. It will be probably at least 4 days before I know for sure.

thanks

Well, I didn't even have to go 4 days - or even 24 hours. It hung at 10:40 this morning and had to be killed through task manager. I have just restarted FF in safe mode with plugins disabled. I guess i will run it a while like that and then try the flash troubleshooting steps.

Ok, I just attempted to added the line protectedmode=0 to the mms.cfg file and i can't save it even logged in with an admin ID with FF not running. Please look at the permissions below and tell me what is needed.

Two ways to edit mms.cfg from an account with admin privileges which is not actually the Administrator account:

(1) On the Start menu, right-click Notepad and Run as Administrator, then edit mms.cfg with that instance of Notepad.

(2) Copy mms.cfg to Documents, edit there, drag back to the real folder to replace the original file.

Two other things:

(1) Safe Mode disables extensions, but doesn't disable plugins. If you want to disable plugins, you still have to do it by hand on the Add-ons page.

(2) If you decide to do the "clean reinstall" again, could you rename the program folder to OldFirefox instead of deleting it? Then you can run a file compare program such as WinMerge against the two directories to see whether files are being changed or added between the time it works normally and the time it starts having problems.

http://winmerge.org/ (free/open source)