Try sending an Email to Avast Support, I think you will have better luck.
support@avast.com
I had trouble inserting my license. If you are running Windows 7, go to control panel, and user accounts, click on change user account control settings, and move the slider all the way down.
Here is an Email from avast telling you how to insert the license.
Dear valued customer,
We have received your request to re-send the license file for your avast! program.
To insert your license, please follow the instructions below:
1. Make sure you have installed either avast! Pro Antivirus or avast! Internet Security on your computer.
2. Your license file is attached to this email. Please save the license file to a secure folder on your hard drive. This file is needed to fully activate your avast! program – it will not install the program so please do not try to open the file before you have installed avast antivirus on your computer.
If you did not receive the attachment, please make sure that your e-mail client and Internet provider allows you to receive attachments and then request your license again.
3. If you have installed avast antivirus on your computer, you only need to double-click on your license file to insert it in the program.
4. Alternatively, open the avast! Interface and click on the Maintenance tab.
Select “Subscription” and then “Insert license file”. Then simply browse your files to locate the file “License.avastlic”. Click on this file to select it and click “Open”.
5. You will be asked if you are sure you want to insert the selected license. Click “Yes”. Your license will now be activated automatically for the valid period of the license.
Note: Your license is valid from the day of purchase, not from the day of activation.
If you have any difficulties inserting the license file please check the link below to find more information.
http://www.avast.com/supportThank you for purchasing avast!
Best regards,
Your avast! team