You can get it from the CD/DVD case.
If you downloaded the programm, the maker should have sent you an e-mail with that information.
It was also displayed in the download page or the next one.
If someone else provided you with that programm, you must deal with him.
Whatever source you used MUST also give you the proper registration key.
If you got it on any P2P channel, it's NOT a valid copy.
Electro, July 2011
