Using multiple profiles in Firefox can be helpful if you are sharing your desktop with others.By using multiple profiles,you can have more privacy over your firefox bookmarks and web history.Check my previous post on how to create multiple firefox profiles for different users.
But if you want to run multiple Firefox profiles simultaneously then pass the ‘-no-remote’ switch together with the name of the profile you want to start with the ‘-P’ switch .
How to run multiple firefox profiles at same time.
1)Create a Firefox shortcut on your desktop.Right click the shortcut and take properties.
2)Add -P profile_name -no-remote to the end of the target as shown below.(where profile_name is the name of the Firefox profile to be started)
3)Click ok and use this shortcut to run that Firefox profile with any other multiple profile at the same time.
By this method you can run two different firefox profiles with 2 different user sessions at the same time.