Done!
I’ve just received the registration email and gone through a different route:
To insert your license key, please follow the instructions below:
- Highlight the license key above, then right-click it and select “Copy”.
- Open your avast! Free Antivirus controls and select the “Settings” tab.
- Next, click the “Registration” tab.
- Click the arrow next to “Offline registration” to expand this option.
- Click the “Insert the license key” button.
- Right-click in the empty Registration box and select “Paste”.
- Click “OK” – your license key is now inserted and your avast! antivirus software can now be used free of charge for a further 12 months.

Thanks again