Right-click the Avast icon in your system tray and select Registration information.
On the My licenses screen, click the Upgrade now button next to Avast Free Antivirus in the list located under Licenses on this PC.
Click Select in the Avast Free Antivirus column.
Click the X icon on the new screen that appears to return to the My licenses screen.
If the above step doesn’t help you to renew avast free antivirus expired license then you can visit our blog to learn more different ways how to extend avast free license?