Have you tried ALL the instructions at...

• Firefox won't start - find solutions

Yes, I have tried all those instructions. None of them work. At the moment, I cannot even uninstall it anymore, because when I do it says all firefox windows need to be closed, even though there are none open according to my Task Manager

Have you tried to delete the firefox install folder manually.

1. Delete the Firefox installation folder, which is located in one of these locations, by default:
   • Windows:
     • C:\Program Files\Mozilla Firefox
     • C:\Program Files (x86)\Mozilla Firefox
2. Reinstall firefox from
   • http://www.mozilla.org/en-US/firefox/all/

I have tried them both - both still say that Firefox cannot be deleted / uninstalled unless you close all Firefox windows, and there are no Firefox windows or Firefox anything open

You can

1. Kill firefox.exe through the Task Manager, to open the taskmanager hit Win + R and enter taskmgr.exe in the window, hit enter, right click firefox.exe and hit "end all processes" or something similar.

OR

2. Boot into safe mode with networking and delete the Firefox install folder said above. See: http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/
For Windows 8: http://www.intowindows.com/shortcut-key-to-boot-into-the-hidden-safe-mode-in-windows-8/

Hi,

Your firefox process got messed up. Please goto Taskmanager by holding "CTRL" + "SHIFT" + "ESC" there you need to go Process Tab please search for Firefox process. Right click on firefox.exe select "End process tree"

And please make a search for any other firefox process on the appropriate tab. If so do the same. And try to open firefox

OR

Please go to "RUN" box and type "firefox /safe" without quotes. It may open.

Thanks, Please let me know if the still persist

See also

• Diagnose Firefox issues using Troubleshoot Mode Please read the article & note
  • Holding the shift key as you start Firefox should start it in Safe mode
  • firefox -safe-mode is used from the commandline / Run
    note space then minus -safe-mode I am not sure /safe works

P.S. When using Task Manager or similar and looking for running Firefox processes also check for plugincontainer

Powering down & restarting the computer may even help.

Ensure that you have no Firefox preloading software installed on your computer.

Trying to open Firefox in Safe Mode is not working. Starting my laptop in safe mode with networking did open firefox for a while, but then it stopped working again, and it switched my WiFi card off in my laptop (that i have switched on again after some searching). I have killed firefox using the processes tab in taskmanager, and have successfully uninstalled it. I am reinstalling it now, hopefully that works.

Thank you very much to everyone. I think that firefox is fixed, as it is open now and working without being slow.

Glad it is fixed. Thanks for posting back.

Note in most cases a simple reinstall of Firefox does not fix problems.

I have this same exact problem but on a new Macbook Pro. I can't start in safe mode or anything. Any suggestions?

Hi bonz812,
Sorry you are having problems.

I assume that you have already scrolled and looked at this current thread and any help articles linked from it.

To get a good answer it is probably best to start your own thread
(As the guidelines suggest).

….  do not re-use existing threads started by others, even if they are seemingly on the same subject.   ….

1. Please use /questions/new
2. Please try to follow the prompts and include troubleshooting info when you do that. (There is a green button to automate the process. Use that, or if you encounter problems doing so mention that in the new thread.)
3. You may wish to post back here; afterwards; to confirm you started a new thread. Others may wish to follow it.

• Note this thread is /questions/970099 (permalinks) ^(meaning) to your question above.