Windows 10 reached EOS (end of support) on October 14, 2025. If you are on Windows 10, see this article.

Avatar for Username

Søg i Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Læs mere
Løst

Firefox error message, "FIrefox is already running but not responding"

Firefox Launch failure
Denys replied
everett_ray
everett_ray

I can't open FIrefox. When I try to open it I get the following error message. "Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window." I opened Task Manager and could not find any instance of Firefox or Mozilla running. I uninstalled Firefox and deleted all the files and folders having to do with Mozilla and Firefox. Then I reinstalled Firefox. I continue to get the same error message. I am running Windows 11 64bit on a Dell laptop. Any suggestions? Ray

I can't open FIrefox. When I try to open it I get the following error message. "Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window." I opened Task Manager and could not find any instance of Firefox or Mozilla running. I uninstalled Firefox and deleted all the files and folders having to do with Mozilla and Firefox. Then I reinstalled Firefox. I continue to get the same error message. I am running Windows 11 64bit on a Dell laptop. Any suggestions? Ray
Vedhæftede skærmbilleder

Alle svar (1)

Denys
Denys
  • Moderator
  • Bidragsyder i top 10

Valgt løsning

Hi,

Please see "Firefox is already running but is not responding" error - How to fix.

Stil et spørgsmål

Du skal logge ind på din konto for at svare på et indlæg. Start et nyt spørgsmål, hvis du ikke har en konto endnu.