I changed the password under settings, and after the successful change and confirmation, when I restarted my PC and tried to go to settings, its not accepting the new or old password.
This isn’t a simple process given the inability to enter a ‘correct’ password, so effectively it has to be done outside of windows running to remove Avast to allow reinstallation.
Regaining access to the Avast program without a password - https://support.avast.com/article/password-protect-antivirus/#pc