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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

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AnonymousUser
AnonymousUser
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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)

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)

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TXGuy
TXGuy
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Kill Application In Task Manager, does firefox.exe show in the Processes tab? See: Kill Application

Causes and solutions for Firefox hanging at exit: Firefox hangs or is not responding - How to fix Firefox hangs at exit "Firefox is already running but is not responding" error - How to fix

Safe Mode You may need to use Diagnose Firefox issues using Troubleshoot 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: Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems Troubleshoot issues with plugins like Flash or Java to fix common Firefox problems Troubleshoot and diagnose Firefox problems

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.