"Go to Start > Run, enter: firefox.exe -p
Create a new profile
In order to use two profiles at the same time, this variable needs to be set:
MOZ_NO_REMOTE=1
Go to Control Panel > System > Advanced > Environment Variables > System Variables > New
Variable Name: MOZ_NO_REMOTE
Variable Value: 1
Click OK, OK, OK
Next, make two shortcuts for Firefox. Each shortcut will be used to launch FF with a different Profile. The target in the shortcut properties will look something like this: Code:
Select allTarget: "C:\Program Files\Mozilla Firefox\firefox.exe" -p "profile name"
You should now be able to launch two separate Firefox sessions."
Forrás innen:
http://forums.mozillazine.org/viewtopic.php?t=185983
Nincs kéznél magyra Windowsom, úgyhogy nem tudom, hogy magyarul mik ezek, remélem nem gond az angol.