Note on moving profiles between operating systems: If you move your profile between dissimilar operating systems (Windows to Mac OS X for example) the path names in the prefs.js file (your settings) may have the wrong syntax. If you're using Thunderbird, you may find Moving your profile folder - Thunderbird easier to follow, since it doesn't cover multiple applications as this article does. If you're migrating from Windows to Linux, you may find Moving from Windows to Linux more useful. However, you may find it easier to share a profile if you move it first to a location whose path doesn't depend upon the user name. In this case you don't physically copy the profile since you're just updating another user's profiles.ini file to use the same profile.