If you forget the password of the
admin administrator, you cannot recover it.
However, you can use the local console to reset the password. For details, see "Resetting passwords" in FortiWeb Administration Guide.
Alternatively, you can reset the FortiWeb appliance to its default state (including the default administrator account and password) by restoring the firmware. For details, see "Restoring firmware (“clean install”)" in FortiWeb Administration Guide.