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I've been tasked with removing Firefox from all Windows workstations in our enterprise environment. Our users don't have local admin, so when they install Firefox, it is installed in the user's profile.

I've just installed Firefox 143.0.1 in my own user profile for testing purposes. However, when I attempt to uninstall, either from Control Panel or by running %localappdata%\Mozilla Firefox\uninstall\helper.exe manually, UAC prompts for elevation, even though I installed without elevating.

I've dug in a bit more, and I found this was an issue five years ago as well:

https://support.mozilla.org/en-US/questions/1286070

According to that post, the issue was resolved, but it seems to have come back.

Any help would be appreciated.

Hi everyone

I used Refresh Firefox option and it created "Old Firefox Data" folder on my desktop.

Awesome stuff. Sadly I cant get rid of it, here is why:

1. At first it said that the folder is used by another program and I cant delete it because of that. Cool, I decided to uninstall Firefox and make a clean install, so I have space to delete the folder too.

2. Long story short, it didnt work. I removed Firefox and tried to delete that folder, but wait for it, yeah I cant because I need permission from MYSELF. Awesome stuff.

3. I decided to use safe mode, so I used run command to run msconfig and I changed it to boot in to safe mode. But wait for it! YES! Its bugged and I cant login in safe mode, because pin is useless and it doesnt give me option to use password, so after hour of various things I got back to my normal mode via CMD commands. THANK YOU MICROSOFT.

4. So now Im stuck with the lovely "Old Firefox Data" folder, which cant be removed normally, neither in safe mode and wait for it! NEITHER WITH ADMIN CMD, not even the takeown /f "Old Firefox Data" /r command. THANK YOU MOZILLA!

So is there someone knowledgeable enough to help me to get rid of that folder pretty please? Like really a lot please.

I looked at the system requirements page at https://www.mozilla.org/en-US/firefox/141.0/system-requirements/ . For Windows devices, the operating systems supported are listed as "Windows 10 or later".

In October 2025, Microsoft officially stops providing feature and security updates for Windows 10. However, they offer consumers and businesses the option of enrolling in 1-year, 2-year, and 3-year subscriptions for Windows 10 devices which will provide another 1-year, 2-years, and 3-years of additional security updates. You can read more about this at https://learn.microsoft.com/en-us/windows/whats-new/extended-security-updates

For those individuals and businesses who will be enrolling devices into the Windows 10 ESU program, will Mozilla continue to support Firefox on Windows 10 after October 2025, at least for those receiving security updates through Microsoft subscriptions? Or at that point will Mozilla consider Windows 11 to be the only supported Windows operating system?

Thank you!

Hello:

When I signed into my computer this morning, a pop-up asked me if I wanted Firefox to update. I let it do that, and then a pop-up came up letting choose among some photos and art for a desktop background. It even let me upload a photo of mine. I chose one of yours, now I can't change to any other photo I have on my computer. Please help.

Thank you,

Cynthia M.

After a windows update I get the following message when I try to open Firefox: The procedure entry point ?ToLogLevel@mozilla@@VA?AW4LogLevel@1@H@Z could not be located in the dynamic link library C:ProgramFiles\Mozilla Firefox\xul.dll Then I get Couldn't load XPCOM

I tried uninstalling firefox but it just hung. I restored it to before the windows update but still got the same message

My Firefox install apparently did a background update that did not complete, I get an error 'XULRunner / Error: Platform version '129.0' is not compatible...'

I did not (do not) have a profile I had logged into for that installation, but did have many passwords saved that I'd like to still be able to use if at all possible.

I have installed another instance of Firefox that is working (on platform 129.0), and am using Windows 11. I also turned off automatic updates in hopes of preventing this in the future.

The previous profile still exists in AppData/Roaming, but I don't know how/if I can connect it to the new installation I now have.

Is it possible to either fix the incomplete update or connect my old profile to this new instance so I don't have to reset all my passwords?

Thanks!

Hi all, I have a docker container which is running Ubuntu 20.04 and the lightweight desktop GUI. I need Firefox up and running in order to access the application for which was the intended use of this container. However the lightweight desktop apparently doesn't have some of the services running like systemd and snap. There is a binary named "Firefox" already installed at /usr/bin/firefox but I've tried "systemctl start firefox" but that didn't work. Any ideas on how to get Firefox up and running? Thanks Norm

After updating a W10 laptop from 115 to 116 of FF the user started having problems with getting to different websites (sites they worked on/with regularly). The problem is the cert DB. The doc I found says that it is cert8.db. Actually it is now cert9.DB.

What I had to do was go to task manager and kill a task that was holding the cert9.db file. Then I could rename it (cert9.old.db). Then restarted their laptop and FF came up and started fixing the cert file (as expected). This seems to have fixed their problem.

I just installed Firefox on a new Windows 11 desktop computer. I ported my profiles over and it appears everything came over EXCEPT: - Themes aren't working. I've tried switching them and they still don't display. The menu bar is black w/white letters; the toolbar is gray with white icons/letters. - My extension icons are there...sort of. If I hover over them I can see the tool tip but the icon doesn't appear on the toolbar which is light gray in color. I can live without the themes if I have to. Not so much the invisible extension icons. Any suggestions as to how I can get them to appear as they do on my Windows 10 desktop? Screen cap below. Cursor is hovered over the Undo Close Tab extension icon but where's the icon? Any suggestions as to how to troubleshoot this will be appreciated!!

Prior to getting some desktop PC upgrades that required a new install of Windows 11 and a new install of Firefox, I backed up my entire PC (yea!).

Now that I have re-installed Firefox, I see that I have none of my saved bookmarks and so I want to restore the Firefox profile - all of it or at least the bookmarks.

I have tried following the Firefox instructions for this, but am apparently not doing it right.

I can't seem to locate the bookmarks file, for starters, in my backed up files. I find the profile but I don't find anything like places.sqlite.

Can someone help me so that I am locating the right (and complete) files, copying them correctly, and then switching to the new/old profile correctly?

Thanks in advance.