If you are using sysinternals desktops with your windows 7 environment, then you have experienced that running another firefox in your virtual desktop is not possible because it will pop up a message that says “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.

sometimes you may just wanted to run IE, Safari, Opera, Chrome at your virtual desktops. That’s not a good solution if you really wanted to just use Firefox.

Here’s a work around
1. right click on the desktop->new and create a shortcut link.
2. Browse firefox exe location usually at c:\program files\mozila firefox
3. click on the firefox.exe
4. on the location of the selected item w/c is “C:\Program Files\Mozilla Firefox\firefox.exe” or any other if you’ve installed it at different location, add (w/o the quotes) “-p -no-remote” to the location w/c makes it “C:\Program Files\Mozilla Firefox\firefox.exe” -p -no-remote
5. click next button and name your shortcut.
6. double click your newly created shortcut and create 4 different profiles or as many as you may need. I made Desktop 1, Desktop 2, Desktop 3, and Desktop 4 for my 4 virtual desktops.

you can now double click your newly created shortcut and choose the appropriate firefox profile for your virtual desktops

If the above fails, try FriendFX’s solution that can be found at

http://support.mozilla.org/en-US/questions/936520

FriendFX suggested to create four different shortcuts for the different Desktops

“C:\Program Files (x86)\Mozilla Firefox\firefox.exe” -p “default”
“C:\Program Files (x86)\Mozilla Firefox\firefox.exe” -no-remote -p “Desktop 2”
“C:\Program Files (x86)\Mozilla Firefox\firefox.exe” -no-remote -p “Desktop 3”
“C:\Program Files (x86)\Mozilla Firefox\firefox.exe” -no-remote -p “Desktop 4”

It worked on my new Firefox Version 19.0.2
happy coding! 😉