Can I disable parent.lock?

Hello,

The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information. Note: This will cause you to lose any Extensions, Open websites, and some Preferences.

To Reset Firefox do the following:

1. Go to Firefox > Help > Troubleshooting Information.
2. Click the "Reset Firefox" button.
3. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
4. Firefox will open with all factory defaults applied.

Further information can be found in the Refresh Firefox - reset add-ons and settings article.

Did this fix your problems? Please report back to us!

Thank you.

You can open only one Firefox instance that uses a specific profile.
You always need multiple profiles if you want to open a second instance with the -no-remote command line switch.

• http://kb.mozillazine.org/Using_multiple_profiles_-_Firefox
• http://kb.mozillazine.org/Bypassing_the_Profile_Manager

Use the -no-remote command line switch to open another Firefox instance with its own profile and to run different Firefox instances simultaneously, but do not use -no-remote with the default browser and the default profile.

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

No you can't disable the parent.lock file. Why do you think you need to disable it?

MOZ_NO_REMOTE =1 is an old pref which isn't needed any longer, The -no-remote command line switch replaced that pref.

Being able to open 2 Firefox windows is normal operation, and has nothing to do with either MOZ_NO_REMOTE or -no-remote .
Are you looking to stop Firefox from being able to open more than one window?