Note that on Windows 7 you can use Firefox 115.4.0 ESR.

• https://support.mozilla.org/en-US/kb/firefox-users-windows-7-8-and-81-moving-extended-support

All Firefox releases on the Mozilla server:

• https://download-installer.cdn.mozilla.net/pub/firefox/releases/
• https://download-installer.cdn.mozilla.net/pub/firefox/releases/56.0.2/

You may have to create a new profile as that is a possible cause for your problems.

• https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles

Make sure to backup your Firefox personal data stored in the Firefox profile folder.

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles
• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

Thank you for the reply cor-el, very useful links. I love my old extensions that would not work in the later versions. Which is why I still use the older version.

this is the error message I received from this mornings backup - Backup encountered a problem while backing up file C:\Users\Sue\AppData\Local\Mozilla\Firefox\Profiles\2nfak06z.default\cache2\entries\7A4321C9FC414A8B27956FFC51989152261C2758. Error:(The request could not be performed because of an I/O device error. (0x8007045D))

I do backup my FF profile every morning, so have it saved from before the crash yesterday while Firefox was working well, and every other day before that too, in case that one is not good.

I'm a bit unsure of the way to install a second copy though. At this link it says to choose a different folder for the custom install. Would it be OK to call the new install folder - new mozilla firefox ? I want to ensure it uses some unused portion of the hard drive.

https://support.mozilla.org/en-US/kb/custom-installation-firefox-on-windows

Also if I rename the current broken profile with a file extension of .old would that prevent the new install from searching for that profile?

If that would work I could simply copy the profile folder that was working fine yesterday morning from the backup drive. I live in hope.

Did you run chkdsk.exe to check the hard drive for errors ? To be able to repair the drive (chkdsk.exe /f /r), you need to do this as administrator and likely need to reboot the computer.

Not done that this time. Will try running it while I cook supper. Currently have 637 re-allocated sectors, 1 pending reallocation and 1 uncorrectable sector. I run Crystal Disk Info constantly.

I have to use an old disk image to copy the contents of the drive to an SSD when I feel up to installing it. Just not been up to it for many months due to ill health. Will have to learn how to do it soon though.

In the past windows has been able to repair the damage by re-allocating the content in the damaged sectors. At least to the point that all the software works and my personal files are not damaged. Firefox is the first victim not to still work. It was the first thing I installed when the computer was new.

cor-el, thank you for the reminder to use chkdsk. It took a really long time to run on restart and I was really trying to stay awake for it to finish so I could read what had been done with each step, got so close too, then woke up to the system rebooting itself! One of the joys of being nearly 70 at almost 2am.

Took me a while to find the chkdsk log, really wish they were easier to find, chkdsk had moved the bad data from that file and today I am happily using Firefox again.

This mornings backup was also successful. Crystal Disk Info still has the same report info as it had yesterday, it has not apparently noticed the changes chkdsk made.

I would still like to install another copy of 56.0.2 in a new folder that will be on an unused part of the hard drive, just in case this happens again.

You can find a link to 56.0.2 in my first reply.

• https://support.mozilla.org/en-US/questions/1430025#answer-1616078

cor-el, I've bookmarked those links in your earlier post, thank you for posting them.

I'm a bit unsure of the way to install a second copy though. At one link it says to choose a different folder for the custom install. Would it be OK to call the new install folder - new mozilla firefox in the same directory? I want to ensure it uses some unused portion of the hard drive.

Also if I temporarily rename the current profile with a file extension of .old would that prevent the new install from searching for or trying to use that profile?

You have two options, save the installer for future use as the installer will complain if it gets corrupted, and the other is doing a custom install in another location.

• https://support.mozilla.org/en-US/kb/custom-installation-firefox-on-windows

I'm confused about where to install the new copy. Currently Firefox is installed in C:\Program Files\Mozilla Firefox\

Could I install the new copy in a folder I create called C:\Program Files\New Mozilla Firefox\

Or would it have to go somewhere else, or be called something else?

I usually let programs install where they prefer to be, this would be the first time I've done a custom install in a different location.

Sure you can install Firefox in a folder with that name, but I thought that you would want to install Firefox on another drive and not on the current system drive (C:).

I only have the one drive on this computer. The backup drive is a portable backup drive.

cor-el, I have marked your post with all the links in it as the solution to my problem in case anyone else has a similar situation.

Thank you for all your help I really appreciate it.