Look on your desktop. Do you see a folder called; Old Firefox? Look inside. Look for the folder with the latest creation date.

https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

http://kb.mozillazine.org/Profile_folder_-_Firefox#Navigating_to_the_profile_folder

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

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Type about:profiles<enter> in the address bar. How many profiles are listed? How many should be there? Also, open the folder in your file explorer.

Hi Larch35, just a footnote that many users have reported Firefox 67's prefs.js file (has the toolbar button layout) and extension database files being more likely to be damaged in system crashes. Unfortunately, I haven't yet seen an explanation for how to avoid this.

If you want to create backups of your extension databases, they are stored together with website offline data in your profile folder:

[profile]\storage\default

Perhaps the whole profile backup would be simpler (although, of course, larger).

If you had irreplaceable data that you need to try to recover, you could look at the shadow copy possibility described in the following thread: https://support.mozilla.org/questions/1261960 -- please ignore the post indicated as the Solution and skip to the end because the poster ended up using a different method

Thanks both. I had no 'Old Firefox' folder on my desktop, but will look into backing up the prefs or whole profile instead.

Back up and restore information in Firefox profiles.{web link} I use an add-on that makes backups of my user profile, Just In Case. Unfortunately, it is not compatible with the current Firefox.

Every now and then, open the profile folder and create a copy of the current profile as is to another location on your hard drive. This way you will have a backup.

If you do this each day, you will not lose much data. This should be done with Firefox Closed.

Note: In case you need to restore from these backups, you may need to overwrite old or corrupted files.

I do not see any solution for stopping the BSOD crashes happening 5X every day since I have tried to use my Bluetooth headset (Bose 35) on Firefox but this only occurs on certain websites and I can watch YouTube and other non-streaming videos all day with Bluetooth. I thought initially it was a FF related issue, but then I tried IE on these sites as well and the BSOD started happening again. Is it the websites themselves, which are different, or Browsers, or Bluetooth glitch, or ???? Spent 50 hours of my life trying to track down the cause including upgrading BIOS, drivers, uninstalling FF and then reinstalling it, etc. etc. Different sites indicate DPC Watchdog Violation and Attempted Switch From DPC as one of the most common Windows complains but nobody seems to be doing any fix for it since it can be caused by s/w, h/w, firmware, O/S, etc. I have an HP Pavilion 11 360 with Windows 8.1 and Bluetooth and every other driver is up to date. Help!!! When I have headset hardwired to my PC, then no problems at all. But that is not why I bought Bluetooth set.

Stan Bailey It sounds like your Bluetooth is causing problems. Contact its support.

After all of my work in testing, my Bluetooth it is working 100% with my iPhone and other apps on my PC. I have also reset the Bluetooth headset per their instructions of Bose as well. All of the sites which I have checked out, which are many, all indicate that this is a Windows O/S related issue and people have been complaining about this same BSOD issue all the way back to 2015 regardless of which Bluetooth device others have used. All of these sites indicate that it is caused by not having updated drivers (which I have), BIOS (which I have updated), Bluetooth pairing with Windows (which is up to date), latest Window 8.1 update (which I also have) etc. One other possibility is the Bluetooth Dongle which is plugged into my HP but it is V4.0 which is the latest also. Therefore, in my mind, it comes down to something is not set correctly in Windows (I even turned off H/W Accelerator which was one suggestion that did not work), or the individual website in which the BSOD crash occurs. If Bluetooth works on the internet with other websites for hours, then why does it crash only on certain sites which have Certificates and are popular sites to watch? It is the mystery of the year for me having tried every recommendation I could find on the internet. I will next contact MS support to seek help from them as well since they have a downloadable app which their support agent can take over my PC and click away to their heart's content.