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

Fresh install won't start - says it's already running even after reboot

  • 10 replies
  • 2 have this problem
  • 1 view
  • Last reply by hippyjim

more options

I've installed Firefox for the first time on this Windows 2008 machine.

The installer quit complaining that Firefox was already in use. I've rebooted twice, and attempted to delete the parent.lock file, and it still won't open.

I can't delete the parent.lock file as it's in use, even after a reboot.

Anyone got any ideas how I fix this?

I've installed Firefox for the first time on this Windows 2008 machine. The installer quit complaining that Firefox was already in use. I've rebooted twice, and attempted to delete the parent.lock file, and it still won't open. I can't delete the parent.lock file as it's in use, even after a reboot. Anyone got any ideas how I fix this?

Chosen solution

It's fixed.

I uninstalled. I deleted the AppData/Roaming/Mozilla and AppData/Local/Mozilla folders, then I reinstalled (this time running the installer as administrator instead of running direct from the browser as the install instructions said).

It worked.

I suspect it was a security policy issue preventing access to the lockfile properly.

Thanks for the suggestions everyone.

Read this answer in context 👍 0

All Replies (10)

more options

Please look at this article, if you have not already done so

The first thing to try is killing the Firefox process (and for that matter any plugin-container). You should kill the process before trying to delete the lockfile.

If all that fails then as suggested in the article you will need to create a new profile and migrate data.

more options

Boot the computer in Windows Safe Mode with network support (press F8 on the boot screen) as a test to see if this helps.

Do you meet the requirements for the current Firefox release?

more options

Thanks - the process isn't running as I haven't *ever* been able to start Firefox. Fresh from boot I can't delete the lockfile - even though there *is no Firefox process running*

I don't have any data or profile to migrate as this is a brand new install of Firefox on a machine that has never had it before. This error happened immediately after the installer finished - Firefox has *never* run on this box.

more options

Thanks for the suggestions.

Booting in safe mode will be awkward as this is a VM I connect to via RDP.

As I mentioned in my question it's Windows 2008, so it should meet the requirements.

Modified by hippyjim

more options

Do you have any utilities to identify the process that has its grips on parent.lock? You may be able to use Process Explorer: http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx

more options

Try to delete the Profiles folder or the Firefox\Profiles and the profiles.ini files to force Firefox to create a new default profile.

  • C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile>\

Note that the "AppData" folder in Windows Vista and later Window 7+ versions and the "Application Data" folder in XP/Win2K are hidden folders.

more options

Weirdly, leaving it a day and reconnecting to the server via rdp again allowed me to delete the lockfile, and indeed the profiles folder.

I'm still getting the same error though. There is *no* Firefox process running. There is *no* Profile folder or lockfile.

I even deleted the profiles.ini file as it pointed to the non-existent profile.

Any more suggestions anyone?

more options

Chosen Solution

It's fixed.

I uninstalled. I deleted the AppData/Roaming/Mozilla and AppData/Local/Mozilla folders, then I reinstalled (this time running the installer as administrator instead of running direct from the browser as the install instructions said).

It worked.

I suspect it was a security policy issue preventing access to the lockfile properly.

Thanks for the suggestions everyone.

Modified by hippyjim

more options

edit

I missed the post above. Partly no doubt the annoying lag on forum listings updates.


Is the entry in the profiles.ini file sane and does it point at a location that has suitable read and write permissions. I am of course assuming if you rename profiles.ini in its current location that Firefox does recreate it.

Presumably after you delete or rename the profile folder Firefox does manage to recreate and populate the profile.

If this is not happening do a clean reinstall of Firefox again, deleting all the Firefox program folders and files prior to the install.

Modified by John99

more options

John99 - no, nothing was recreated after I attempted to run again, but as I said, uninstalling and reinstalling as administrator fixed this.Thanks anyway.