I’m going to change the operational system from Windows Vista to Windows 7. How do I reinstall my avast license?
you still have the mail with the license click file ?
then just download the program again and enter the license file…
avast! 6.x: Inserting the license file into avast! Pro Antivirus
https://support.avast.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=682
avast! 6.x: Inserting the license file into avast! Internet Security
https://support.avast.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=652