Double click "Nero9_Plug-ins.reg".
Double click "Nero-188.8.131.52d_update" to extract installation file.
Go to C:/Program Files/Nero184.108.40.206c or where you extracted the installation file.
Double click "Nero9" for installation. The serial is already entered during installation.
Double click "Activation.reg" in your original torrent folder.
Go to "C:/Program Files/Common Files/Nero/AdvrCntr4", and delete the following:
Edited from anony014's giude.
If you still need the serial: Run regedit - HKEY_LOCAL_MACHINE/SOFTWARE/Nero/Shared/NL9. The first serial9 is your serial #. It starts with 9M03-...