yes, but there's no need to edit the registry.
in the main Nero Express window, click on the ? button, one of the options is "Enter new serial number".
of course you need to purchase that serial number first.
as for your original question, cfitz answered it just fine
i've nothing more to add.
One Ring to rule them all, One Ring to find them,
One Ring to bring them all and in the darkness bind them
In the land of Mordor, where the Shadows lie
M.C. Escher - Reptilien