Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I would like to open a new instance of Firefox. I tried

firefox -no-remote


MOZ_NO_REMOTE=1 firefox

as detailed in the docs. However I keep getting the message

Firefox is already running, but is not responding. To open a new window, 
you must first close the existing Firefox process, or restart your system.

How can I launch a new instance of Firefox from command line?

share|improve this question
You can use something like firefox -url www.mozilla.com or just firefox www.mozilla.com to open a new instance of the browser in a new window. –  martineau Feb 16 '13 at 20:26
@martineau I dont think you understand "new instance". That is 2 processes of firefox. –  Steven Penny Feb 16 '13 at 20:30

2 Answers 2

up vote 4 down vote accepted

The -no-remote option is used for running multiple Firefox profiles at the same time. You are getting the "Firefox is already running" message because you are trying to open a second Firefox instance with the same profile.

You should be using this option as follows:

firefox -no-remote -P "Another Profile"


firefox -no-remote -profile "profile_path"

where profile_path is an absolute or relative (to firefox.exe) path.

share|improve this answer

Resetting firefox can fix major problems,and also delete the adwares View more details- http://tech4computers.blogspot.in/2013/11/reset-mozilla-firefox-setting.html

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.