To register the program, you may open Golden Video, click on the menu File at the upper left-hand corner, select Register Software, enter the code sent to you by email, and click on Register.
Regarding the issues with the audio, is this happening while you are recording or when you preview the recorded video?
For more details about how to use the program you may want to follow this link http://help.nchsoftware.com/help/en/goldenvideos/win/index.html