I'm running the most recent version of windows 7 64 Bit Home and downloaded the latest update to Avast Free last night (9/20/2019). After the update finished and I rebooted, I was unable to open Firefox 64 bit, the latest version of Chrome and the latest version of Thunderbird. It only seemed to effect these 3 programs. I uninstalled a bunch of updates to windows, other programs nothing worked. When I uninstalled Avast it fixed the problem, standard uninstall - not safe mode with Avast Clear program. Reinstalled Avast, same problem. Uninstalled in Safe Mode with the Avast Clear, then reinstalled. Same problem. Before I switch to another Free Antivirus, was hoping to fix the problem and re-install Avast.
Any help will be appreciated!