Avast must be having a good laugh at people using it’s software.

If you have to disable the hosts file just to install their software, then something is not right at Avast. It would suggest Avast is more spyware than antivirus.

Did you notice Avast attempts to send a hardware key and the windows system name to a hostname at program.avast.com during the uninstall process. You might want to add that hostname into the hosts file too and point it to 127.0.0.1.

The safest way to use Avast is to firewall it. Don’t let it connect out at all.