Mozilla Master Password Recovery Screenshots:
selecting Master Password location

Select the folder where the program (Mozilla, SeaMonkey,Firefox, or Thunderbird) stores its Master Password. Normally, Mozilla Password Recovery does that automatically and allows you to select the folder manually if you have two or more programs installed on your computer. You can also do that by hand by entering path to the key3.db file. It is stored in the program's profile. For example:
C:\Documents and Settings\John\Application Data\Mozilla\Firefox\Profiles\3un7ntgo.default\key3.db.