Let's see if we can find your data.

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 profile folder in your file explorer.

hell, thank you for responding but this did not work. it seems to me the old version of Firefox is somewhere on this machine. it would be nice if I could access it. Would it help to delete the new version ?

also to answer your question there is no "old firefox" icon on my desktop, just the one with the half eaten logo

Hi paubry

What is wrong with your Firefox 80 version that you do not like ?

There are hardly differences between Firefox 79 and 80 in the way it works.

my bookmarks etc are gone. They are supposed to sync (yes sync is turned on !!) but they did not which is very annoying. it wants me to "add a device" but I dont have another device, and even if I did I wouldnt want to add it. I been using Firefox for many years, and have updated it before without this problem. Please help !! I need a simple solution. Thanks