To activate your software you need your Hardware ID.
This can be found in the startup dialog or for demo versions in the About dialog:
Now go to Software, select the appropriate version and click 'Activate'. On the new page enter the product code that has been send to you and after code verification enter your personal and the Hardware ID and an email with a license file will be send to you. Copy this file to any place on your computer and use the 'Install License' button to install license. Restart your program and you are done.