Avast Internet Security will not work after reinstalling Windows 7

I have been using Avast Internet Security for three years and my subscription automatically renewed in April 2017. Ten days or so I decided to set my computer back to factory settings - effectively a reinstall of Windows 7. After successfully installing Windows 7 I installed Avast Internet security and used my License file which did not make my internet Security work and it persisted in saying my License had expired.
I have been in contact with Avast Support who advised me to uninstall Avast internet security using their special uninstaller which I did. They also issued me with an Activation code but although it did work for a few hours it wasn’t long before it came up with another message saying I was in danger and my licence had expired.

I am presuming that perhaps i should have uninstalled Avast Internet security first before reinstalling Windows 7 as I am presuming that the Avast computers think I have it installed on two computers.

I have tried to contact Avast Support again without success.
I feel somewhat let down by Avast as I have paid for a years subscription and it looks as if I am going to have to accept that I have lost the money.
Is there anything else I can do. Is there anyone who can help.
Thank-you.
Michael Houghton

“I installed Norton Internet security and used my License file” ???

After successfully installing Windows 7 I installed [b]Norton Internet security[/b] and used my License file which did not make my internet Security work and it persisted in saying my License had expired.