When trying to render to mp3, I got a pop up saying I needed to register.
There were two choices, one if the PC was on Internet, the other was "Register on another computer."
I chose the second, followed the prompts and saved the registration request to a Flash Memory stick (Floppy or RW CD can also be used)
Took the Flash stick to my Internet computer, double clicked the file and it took me to Sony's site. After following instructions, an email with an Activation code was sent to me. I copied this into the registration box on the original computer, and this is now registered and working.