You must contact Helpdesk with your serial number as given in either email or printed form.
The 'beta expired' message means that it's either a illegitimate copy, or a pre-release copy, or something has gone wrong at N3V's end (which is rare in serial number terms)
To register a serial number, you can click Serial Number above, and fill in the form, although wait for instructions from Helpdesk first.
Shane