MozBackup 1.4.8 is a freeware utility for Microsoft Windows that lets you easily backup and restore profiles for Mozilla Firefox, Thunderbird, and SeaMonkey. I just tried as part of the long list of things I need to do to migrate from my main Windows XP PC to a new PC running Windows Vista. Thunderbird started up with all my email account profiles intact on the Vista end after restoring from the backup file MozBackup created. Thumbs up for this little utility.