Avast says my serial number is invalid. I’m looking for advice. Thanks - Dane
do you use avast! home?
here you can get a new serial which can be entered in the program:
http://www.avast.com/eng/home-registration.php
yours
onlysomeone
This is in fact a ‘feature’. 
Just insert you license number again.
It’s a part of the antipiracy methods of avast…