That does nothing at all related to MAC addresses - it you want to use them, you will first have to retrieve it. This will help: Retrieving IP and MAC addresses for a LAN
] - there is a method there to retrive the current PC MAC address.
But - don't waste too much time on this: MAC addresses can be spoofed, a PC will only have a MAC address if it has an active network connector, and most software protection methods annoy legitimate users more than they inconvenience pirates. You have to decide what level of piracy you are likely to get, how many of those can be converted into sales by protecting the software and the cost of the time to implement protection. Very often, it just isn't worth the effort...