Got the email my Free expires in 12 days, but Avast is not showing me how to renew it.
This is on the Win 7 side of my dual-booting 7+10 machine, and if I cannot renew Avast Free for the 7, I’m just going to ditch 7 and move everything to the 10, which I have to do soon anyway. On 10 I am using Windows Defender.
So - what buttons do I push to renew Free?
Need to wait for a renew option via the UI when you check your license.
The other option is to do a clean install. 
At some point the UI should change and what is the Upgrade button bottom left of the main UI window, should change to Activate.
Also if you right click on the Avast Tray icon and select Registration Information you should see your existing Subscription/license information. If it is close to expiry the drop down list should allow to renew/activate.