I had responded that I was UnInstalling Firefox entirely!!

[paulhart2]

I had responded that I was UnInstalling Firefox entirely!! when questioned during uninstall routine. I ran Fortect, after uninstall, and did a full re-fresh of my Windows 11 Pro installation.
The good news is that, even tho Firefox was difficult to uninstall??, eventually I removed it and all related folders. After a successful re-boot, I re-installed Firefox, and the progress bar actually moved across the screen, which it did not do before. After re-Install, Firefox returned to normal functionality, despite the headache of having to re-enter all of my passwords, once again. Good to have it back. Annoyed that it took so much effort?? Finally successful!!!

[dftf]

Shouldn't be that difficult, there's only like five folders.

Uninstall Firefox normally first, then delete these (see warnings after):
C:\ProgramData = one in there that starts "mozilla" then a series of numbers
C:\Program Files (x86)\Mozilla Maintenance Service
C:\Program Files\Mozilla Firefox
C:\Users\<yourusernamehere>\AppData\Local\Mozilla\Firefox
C:\Users\<yourusernamehere>\AppData\Roaming\Mozilla\Firefox

⚠ You should not remove the "mozilla-" one in the "ProgramData" folder, or the "Mozilla Maintenance Service" one if you also have Thunderbird installed; it may stop working.

⚠ The location with "Roaming" in is where your personal Firefox data goes (bookmarks, history, passwords, addresses, credit-cards, extensions, and so-on).  Only delete it if you've exported what you need first.