Creating a new Profile

Warning
If you are running multiple versions of Firefox, this may not work for you.


1) make a copy of your Firefox startup shortcut and rename it to something like FF Profile Manager

Add  -ProfileManager to the end of the string in the target box

example
...\firefox.exe -ProfileManager


2) make another copy of your Firefox startup shortcut and rename it to something like FF CookBook

Add  -P CookBook to the end of the string in the target box
example
...\firefox.exe -P CookBook


3) set an environment variable
MOZ_NO_REMOTE to 1


make sure all instances of Firefox are stopped, not running, finito

4) click on the shortcut you created in 1
    create a profile, lets say you name it CookBook so that it will match what you did in the shortcut in 2 - P CooklBook
    exit Firefox

5) when you click on the shortcut you created in 2, it should start you in this new profile.
    use this profile to install and access the extension

for more information, you go here

http://the-edmeister.home.comcast.net/advice-html/simultaneous-profiles_versions.html