Hello chandlercrouch, If you deleted your only profile folder, and now seeing the "already running" dialog box, delete or rename the profiles.ini file in the profile folder path. A new default profile will be created when you next start your Mozilla application.

thank you

A possible cause is security software (firewall,anti-virus) that blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.

Remove all rules for Firefox and the plugin-container from the permissions list in the firewall and let your firewall ask again for permission to get full unrestricted access to internet for Firefox and the plugin-container process and the updater process.

See:

• https://support.mozilla.org/kb/Server+not+found
• https://support.mozilla.org/kb/Firewalls

• http://kb.mozillazine.org/Browser_will_not_start_up

@ideato the profile isn't an issue. I deleted the profile folder, all cookies etc, and uninstalled firefox to make sure my system was clear of any previous settings that could mess things up... then I installed firefox. Upon installation, firefox created a completely new profile.

@cor-el I completely disabled all security, then reinstalled and observed no changes.

I sincerely appreciate both of your replies. Do you have any other ideas about what could be causing the problem?

The profiles.ini file contains information used to keep track of profiles in Firefox, if you have a new profile but you can not open it then delete the profiles.ini file.

the profiles.ini file it is not inside profile folder. it is in %APPDATA%\Mozilla\Firefox , but not inside profile folder

thanks again

Try to boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that helps.

@cor-el ahhh, thank goodness... progress. You're smart. It started in safemode. It feels great, but doesn't solve the problem entirely. How do I troubleshoot from here?

I just executed the plugin for the automatic trouble shooter. It saved a bunch of stuff under my original question post.

Which problems are still left?

If it works in Windows Safe mode then you have a problem with other software, likely security software or a system driver, that is running on your computer.
Make sure that you have the latest updates of your security software.

You can use the Autoruns utility to see which software and services gets started, but be careful with disabling services.

• http://technet.microsoft.com/en-us/sysinternals/bb963902.aspx