Profile with mail settings and stuff is in C:\Windows.old\Users\\AppData\Roaming\Thunderbird\Profiles\.default\
%AppData% resolves to the Roaming directory, not the Local one. This is even if the email folders have been stored elsewhere.
See https://support.mozillamessaging.com/en-US/kb/profiles#w_restoring-a-profile-backup
Useful information about passwords
http://kb.mozillazine.org/Setting_and_changing_email_passwords
