This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search 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.

Learn More

After firefox update last night to 36.0.4, it is not starting?

  • 1 nzaghachinzaghachi
  • 1 nwere nsogbu anwere nsogbu a
  • 37 views
  • Nzaghachi ikpeazụ nke guigs

more options

After firefox update last night to 36.0.4. I cannot open Firefox. It says Firefox is already running, but is not responding. The old Firefox process must be closed to open. I try to close it under task manager, it is not listed under process but under details - Cannot end task, as it says access is denied. I try to look for help on the net. It says to delete the file PARENT.LOCK, It says action cannot be complete as the file is open in Firefox. I try to shut down my computer, even log out on my current user but cannot delete the file Parent.lock. I am using a win 8.0 The easiest way is to uninstall and to install a fresh application, but will this wipe out all my bookmarks etc....

Thanks, Coco

After firefox update last night to 36.0.4. I cannot open Firefox. It says Firefox is already running, but is not responding. The old Firefox process must be closed to open. I try to close it under task manager, it is not listed under process but under details - Cannot end task, as it says access is denied. I try to look for help on the net. It says to delete the file PARENT.LOCK, It says action cannot be complete as the file is open in Firefox. I try to shut down my computer, even log out on my current user but cannot delete the file Parent.lock. I am using a win 8.0 The easiest way is to uninstall and to install a fresh application, but will this wipe out all my bookmarks etc.... Thanks, Coco

All Replies (1)

more options

Hi Coco, Thank you for your question, since the parent.lock file cannot be removed it is possible to create a new profile: