Are you seeing this?

Or maybe you're already seeing this?

The solution is simple (and you don't have to give up any money, either!). Click on the links where I have indicated red arrows. From the first picture, you will then see this:

Choose "Re-register Avast Home Edition." It will then send you to their site to fill out some brief information, like below:

Fill out the form, and then Avast will send you an email with your new registration key and instructions on how to insert the key. You're done!