I want to upgrade from the free version to Avast Pro Antivirus or Internet Security. How do I do this?

First of all, there is no need to uninstall your free version. After purchasing the version Pro Antivirus or Internet Security, you will receive a new licence key. You then simply need to enter the new licence key into Avast. Avast will download the additional components and immediately update itself to the Pro Antivirus or Internet Security version.