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firefox won't open and keeps prompting for permission to make changes

jhazlip
jhazlip
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We updated the machine from Win 7 to Win 10. (Firefox worked before the update). After the update was complete, we tried to open Firefox and was prompted with the Windows 10 "User account control" permission prompt window. If we click YES on the UAC window, it closes and comes back (the User Account Control window).

I cannot get Firefox to open. the UAC window just keep re-appearing no matter how many times I click yes. I tried uninstalling re-installing. Same result. I tried uninstalling and installing Version 71 (the current version is 72). Version 71 opened 1 time. Then I closed it and re-opened it, The same UAC prompt appears and the issue repeats.

We updated the machine from Win 7 to Win 10. (Firefox worked before the update). After the update was complete, we tried to open Firefox and was prompted with the Windows 10 "User account control" permission prompt window. If we click YES on the UAC window, it closes and comes back (the User Account Control window). I cannot get Firefox to open. the UAC window just keep re-appearing no matter how many times I click yes. I tried uninstalling re-installing. Same result. I tried uninstalling and installing Version 71 (the current version is 72). Version 71 opened 1 time. Then I closed it and re-opened it, The same UAC prompt appears and the issue repeats.

All Replies (4)

cor-el
cor-el
  • Moderator
  • Top 10 Contributor
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Try to uninstall Firefox and reinstall Firefox as a normal user.

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

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 the current Firefox version, because this will remove all profile folders and you lose personal data like bookmarks and passwords including personal data in profiles created by other Firefox versions

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

  • (64-bit Firefox) "C:\Program Files\Mozilla Firefox\"
  • (32-bit Firefox) "C:\Program Files (x86)\Mozilla Firefox\"
  • it is important to delete the Firefox program folder to remove all the files and make sure there are no problems with files that were leftover after uninstalling

Your personal data like bookmarks is stored in the Firefox profile folder, so you won't lose personal data when you reinstall or update Firefox, but make sure NOT to remove personal data when you uninstall Firefox as that will remove all Firefox profile folders and you lose your personal data.

Reinstall Firefox

Modified by cor-el

jhazlip
jhazlip Question owner
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Thanks, but there is only 1 user account on the machine. When I re-installed the 2nd time, I deleted all Mozilla folders under:

  • C:\Program Files\
  • C:\ProgramData\
  • %USERPROFILE%\AppData\Local\
  • %USERPROFILE%\AppData\Roaming\

It may be a registry key, but i don't know what key it would be.

I disabled UAC prompts on the machine and started firefox to see what it would do. No window ever appeared. In task manager Firefox.exe just kept restarting over and over.

crankygoat
crankygoat
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Well, first, you did delete your profile, so if you had a lot of bookmarks and logins, etc., you might want to fish that out of the recycle bin if it is still there. If not, use a free data recovery app, e.g., https://www.ccleaner.com/recuva/features/portable-version and run it from a flash drive. Stop using the computer with the deleted profile entirely until you recover your profile, if you want it back. It was in C:\Users\<username>\AppData\Roaming\Mozilla\Firefox\Profiles\

user104147805413306348376805769878442569366
user104147805413306348376805769878442569366
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If you can't recover your data with @crankygoat's suggeston, and you have a System Restore Point available, try this:

ShadowExplorer https://www.shadowexplorer.com/