When I try to start Firefox I get Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.

I get this message when I try to start Firefox after first logging on after turning on the computer.
Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.
Have rebooted. Works when Administrator logs in, just does this in my user profile. Have also re-intalled. Mo change in my User account.
Firefox was working fine for the last 3 1/2 years. Any suggestions?

Firefox is "hanging at exit" when you exit/quit Firefox. 
#Stop the Firefox process:
#*[http://kb.mozillazine.org/Kill_application Mozillazine - Kill application]
#*Windows 7 users click [http://www.techrepublic.com/blog/window-on-windows/reap-the-benefits-of-windows-7s-task-manager/2576 here]
#*Mac users: http://techheavy.com/2011/02/the-mac-task-manager/
#Why Firefox may hang:
#*[http://support.mozilla.com/en-US/kb/Firefox+hangs Firefox hangs] (see Hang at exit)
#*[http://kb.mozillazine.org/Firefox_hangs Firefox hangs (Mozillazine)] (see Hang at exit and Closing Firefox properly)
#*[https://support.mozilla.com/en-US/kb/Firefox+is+already+running+but+is+not+responding Firefox is already running but is not responding]
#Use Firefox Safe Mode to find a problem with an Extension or Plugin:
#*Don't check anything when entering Safe Mode, just continue
#*If the problem does not occur in Safe Mode it is probably and Extension or Plugin causing the problem
#*See:
#**[[Safe Mode]] and [http://kb.mozillazine.org/Safe_Mode Safe Mode (Mozillazine)]
#**[http://support.mozilla.com/en-US/kb/Troubleshooting+extensions+and+themes Troubleshooting extensions and themes]
#**[http://support.mozilla.com/en-US/kb/Troubleshooting+plugins Troubleshooting plugins]
#**[http://support.mozilla.com/en-US/kb/Basic+Troubleshooting Basic Troubleshooting]
'''If this reply solves your problem, please click "Solved It" next to this reply when signed-in to the forum.'''

Similar Messages

I try to launch firefox get the following message "firefox is already running, but is not resonding. to open a new window, you must first close the existing firefox process, or restart your system" firefox is not running and restart doesn't work

when I launch firefox get the following message "firefox is already running, but is not resonding. to open a new window, you must first close the existing firefox process, or restart your system" firefox not running and a restart doesn't solve the problem

Download a fresh Firefox copy and save the file to the desktop.
*Firefox 12.0.x: http://www.mozilla.org/en-US/firefox/all.html
Uninstall your current Firefox version, if possible.
*Do NOT remove personal data when you uninstall your current Firefox version, because all profile folders will be removed and you will also lose your personal data like bookmarks and passwords from profiles of other Firefox versions.
Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.
*It is important to delete the Firefox program folder to remove all the files and make sure that there are no problems with files that were leftover after uninstalling.
*http://kb.mozillazine.org/Uninstalling_Firefox
Your bookmarks and other profile data are stored elsewhere in the Firefox Profile Folder and won't be affected by a reinstall, but make sure that you do not select to remove personal data if you uninstall Firefox.
*http://kb.mozillazine.org/Profile_folder_-_Firefox
See also:
*https://support.mozilla.org/kb/Firefox+is+already+running+but+is+not+responding
*http://kb.mozillazine.org/Profile_in_use
*http://kb.mozillazine.org/Recovering_a_missing_profile

When i close firefox and then attempt to restart it i get the following message. firefox is alreadt running,but is not responding to open a new window.you must first close the existing firefox process or restart your system.

i have to restart

Sounds like Firefox is "hanging at exit". That problem is frequently caused by an Extension or a Plugin. Read all of the following articles. 
#Stop the Firefox process:
#*[http://kb.mozillazine.org/Kill_application Mozillazine - Kill application]
#*Windows 7 users click [http://www.techrepublic.com/blog/window-on-windows/reap-the-benefits-of-windows-7s-task-manager/2576 here]
#*Mac users: http://techheavy.com/2011/02/the-mac-task-manager/
#Why Firefox may hang:
#*[http://support.mozilla.com/en-US/kb/Firefox+hangs Firefox hangs] (see Hang at exit)
#*[http://kb.mozillazine.org/Firefox_hangs Firefox hangs (Mozillazine)] (see Hang at exit and Closing Firefox properly)
#*[https://support.mozilla.com/en-US/kb/Firefox+is+already+running+but+is+not+responding Firefox is already running but is not responding]
#Use Firefox Safe Mode to find a problem with an Extension or Plugin:
#*Don't check anything when entering Safe Mode, just continue
#*If the problem does not occur in Safe Mode it is probably and Extension or Plugin causing the problem
#*See:
#**[[Safe Mode]] and [http://kb.mozillazine.org/Safe_Mode Safe Mode (Mozillazine)]
#**[http://support.mozilla.com/en-US/kb/Troubleshooting+extensions+and+themes Troubleshooting extensions and themes]
#**[http://support.mozilla.com/en-US/kb/Troubleshooting+plugins Troubleshooting plugins]
#**[http://support.mozilla.com/en-US/kb/Basic+Troubleshooting Basic Troubleshooting]
'''If this reply solves your problem, please click "Solved It" next to this reply when signed-in to the forum.'''
Not related to your question, but...
You may need to update some plug-ins. Check your plug-ins and update as necessary:
*Plug-in check --> http://www.mozilla.org/en-US/plugincheck/
*Adobe Shockwave for Director Netscape plug-in: [https://support.mozilla.com/en-US/kb/Using%20the%20Shockwave%20plugin%20with%20Firefox#w_installing-shockwave Installing ('''''or Updating''''') the Shockwave plugin with Firefox]
*Adobe PDF Plug-In For Firefox and Netscape: [https://support.mozilla.com/en-US/kb/Using%20the%20Adobe%20Reader%20plugin%20with%20Firefox#w_installing-and-updating-adobe-reader Installing/Updating Adobe Reader in Firefox]
*Shockwave Flash (Adobe Flash or Flash): [https://support.mozilla.com/en-US/kb/Managing%20the%20Flash%20plugin#w_updating-flash Updating Flash in Firefox]
*Next Generation Java Plug-in for Mozilla browsers: [https://support.mozilla.com/en-US/kb/Using%20the%20Java%20plugin%20with%20Firefox#w_installing-or-updating-java Installing or Updating Java in Firefox]

I often get this message. Firefox is already running but is not responding.To open a new window you must first close the excisting Firefox process or restart your system.Thankyou Colin.

So this message appears mainly if I were changing web sites.Can't carry on until I have cleared everything from screen,gone on to my Thunderbird e-mail then Firefox will load again.I can then just carry on till next time.

Please look at [[Firefox is already running but is not responding]]
The initial problem is solved by killing any process firefox.exe, ( & maybe also plugincontainer.exe) Make sure you always close firefox by using the option Firefox Button -> Exit
You may need to investigate further and clear some of the duplicated files that may exist.

When I try to accessFirefox, I get a message that says Firefox is already running ,but is not responding.To open a new window,you must first close the

I get this message when I click the icon on the desktop or open a webpage from O.E.

Make sure that you do not start Firefox with the -no-remote switch appended to the command line.
* http://kb.mozillazine.org/Opening_a_new_instance_of_Firefox_with_another_profile
See also:
* http://kb.mozillazine.org/Profile_in_use
* [[Firefox is already running but is not responding]]

I open firefox it keeps saying"Firefox is already running,but not responding.To open a new window,you must first close the existing Firefox process,or restart your system" i tried restart my computer...but it's still keep saying that..pls help me..

As I stated above, I have to constantly restart my computer because I get a message stating firefox is already running.

Do you see a firefox.exe in the Task manager if you look there right after you get this error message?
You do not have to restart the computer, just kill that process.
This situation may occur if Firefox was not closed correctly or crashed.

Why does firefox stop loading then when i close it and try to open it up again I keep getting this message:Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system

Firefox will just stop loading/ connecting to the internet. The gray circle will just continually move but it never turns green to load the pages. I know it's not my internet because my internet explorer works just fine while this is happening to firefox. So I close firefox and then try to re open it but I get the message: Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system. So I wait a little bit then try and re open it and still get the same message. I then go into my windows task manager and try and end the firefox proccess but it won't end. So I restart my computer and firefox eventually starts acting up again.

For possible causes of this error, and how to troubleshoot it see [[Firefox is already running but is not responding]].

I consistently get this messsage and have to restart the system - "Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system". When I look at the Task Manager no Fire

I consistently get this message and have to re'boot my system. "Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system"
== User Agent ==
Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; GTB6.5; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET CLR 3.0.04506; InfoPath.2; Media Center PC 5.0; SLCC1)

'''Kill Application'''
In Task Manager, does firefox.exe show in the '''Processes''' tab?
See: [http://kb.mozillazine.org/Kill_application Kill Application]
'''Causes and solutions for Firefox hanging at exit:'''
[[Firefox hangs]]
[http://kb.mozillazine.org/Firefox_hangs#Hang_at_exit Firefox hangs at exit]
[[Firefox is already running but is not responding]]
'''Safe Mode'''
You may need to use '''[[Safe Mode]]''' (click on "Safe Mode" and read) to localize the problem. Firefox Safe Mode is a diagnostic mode that disables Extensions and some other features of Firefox. If you are using a theme, switch to the DEFAULT theme: Tools > Add-ons > Themes '''before''' starting Safe Mode. When entering Safe Mode, do not check any items on the entry window, just click "Continue in Safe Mode". Test to see if the problem you are experiencing is corrected.
See:
'''[[Troubleshooting extensions and themes]]'''
'''[[Troubleshooting plugins]]'''
'''[[Basic Troubleshooting]]'''
If the problem does not occur in Safe-mode then disable all of your Extensions and Plug-ins and then try to find which is causing it by enabling '''one at a time''' until the problem reappears. '''You MUST close and restart Firefox after EACH change''' via File > Restart Firefox (on Mac: Firefox > Quit). You can use "Disable all add-ons" on the Safe mode start window.

Iget this when I try to open a session....Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.task mngr shows no open firefox processes.

I get this when I try to open a session....Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.The task manager shows no open Firefox processes.I had two users on this laptop running Firefox and I tried deleting the program on both users. I then downloaded the newest version, installed it and I still get the error message as before. HELP!!!! I loved the browser program when it was working before and would rather use it than other browsers.

See "Hang at exit":
* http://kb.mozillazine.org/Firefox_hangs
* https://support.mozilla.com/kb/Firefox+hangs

I always get the message "Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system." on terying to run firefox

When I try to run Firefox I get the message "Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system."
No copy of firefox is running as far as I can tell. Restart and restoring system to 10 days ago did not help.
Uninstalling and downloading a new copy - but to not avail.

See:
* http://kb.mozillazine.org/Recovering_a_missing_profile
* http://kb.mozillazine.org/Profile_in_use
Do you still have a default profile? 
If not then delete the file [http://kb.mozillazine.org/profiles.ini_file profiles.ini] to make Firefox create a new default profile.
* C:\Documents and Settings\<user>\Application Data\Mozilla\Firefox\Profiles\<profile>\

Firefox is OPEN and working fine, but when I click a link in Thunderbird I get 'Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.'

If I click a link on my desktop or in any other program (while Firefox is open and running), I get this message: "Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system." There's about a billion links for this if you Google it, but they all say that Firefox wasn't shut down properly. (OK, maybe not ALL of them, but if the needle is in that haystack, I haven't yet found it.) That's not the issue in my case since I haven't shut FF down at all.
== This happened ==
Every time Firefox opened
== IDK

This began to happen to me when I tried to run two separate profiles simultaneously on the same installation of firefox with -no-remote

Doesn't start when starting as administrator. Error Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.

Update firefox, it asked me to update flash, I tried to update flash but it said I had to close firefox. A box came up and said the Flash install would continue when I closed firefox. I closed all firefox windows and no update of flash occurred. I tried relaunching firefox but got the "Doesn't start when starting as administrator. Error Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system." message. I rebooted the system, no improvement. I tried to run firefox as administrator and got the same message. Either I find a fix or I won't be able to use firefox and will have to go back to ie.

-> press '''CTRL''' + '''SHIFT''' + '''ESC''' to Open Task Manager -> Processes tab -> right-click '''firefox.exe''' and click '''End Process Tree''' -> close Task Manager
Troubleshooting extensions and themes
* https://support.mozilla.com/en-US/kb/Troubleshooting%20extensions%20and%20themes
Troubleshooting plugins
* https://support.mozilla.com/en-US/kb/Troubleshooting%20plugins
Check and tell if its working.

I keep getting this message after closing Firefox and attempt to reopen-Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.

I keep getting this message after closing Firefox and attempt to reopen-Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.

See:
* http://kb.mozillazine.org/Recovering_a_missing_profile
* http://kb.mozillazine.org/Profile_in_use

Sometimes when I close Firefox and try to open it in few moments it shows me message "Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system." However, I haven't o

Sometimes when I close Firefox and try to open it in few moments it shows me message "Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system." However, I haven't opened any additional Firefox related programs, and previous Firefox is closed. First I though it is because of my computer, but then I discovered that other people have the same problem as well
== This happened ==
A few times a week
== some 2 month ago ==
== User Agent ==
Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; SLCC1; .NET CLR 2.0.50727; Media Center PC 5.0; .NET CLR 3.5.30729; InfoPath.2; .NET CLR 3.0.30729)

Hi Andis.
First of all, this is completely normal behavior, although it's a bit irritating, I know. What happens is that when you close Firefox, despite the window disappearing right there and then, Firefox keeps running for a little bit until the whole closing procedure is completed. This can take a fraction of a second on fast computers, or can take a few seconds on slow computers or when Firefox is storing a large session (if you save your tabs). All you have to do is wait a bit until Firefox closes, and then open it again.
To see if it's still running, you can press CTRL+SHIFT+ESC and then, under the Processes tab, you can see if firefox.exe is still there. If it's taking an unusual amount of time to close (which happens very rarely, and only if the browser freezes on exit), you can force the application to terminate from this application (task manager).
Firefox 4.0 will reduce by 97% the time it takes firefox.exe to close, so this problem will be basically erased for Firefox's next version.
Until then, I can recommend you this extension, which helps you restart your browser more easily and without bothering about closing times:
https://addons.mozilla.org/en-US/firefox/addon/3559/
Hopefully this will help.

I get this warning on firefox a lot...."Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.

'''''Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.''''' this is a message I get a lot. Whats happening? Thanks Tony'

See "Hang at exit":
* http://kb.mozillazine.org/Firefox_hangs
* https://support.mozilla.com/kb/Firefox+hangs

When I try to start Firefox I get Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.

Similar Messages

Maybe you are looking for