I have trouble extending the free license, which will expire in a week. I tried extending it and selecting “Avast Free Antivirus” in the “Select your security level” dialog, and it takes me to the “Thank you for activating …” dialog, with the only option to “Continue with upgrade”. At that point I closed the dialog, cos doing anything else only starts the trial for the premium service. However, Avast still notify me to extend the license. So how do I properly extend the free license?