Being that you still have the Alwil name there I'd suggest a clean install using the removal tool
http://www.avast.com/uninstall-utility in safe mode and reinstalling the latest avast fresh.
Avast hasn't used the Alwil name since the early 5 versions.
Download a new copy of avast and the removal tool I linked to and save, then uninstall avast normally via remove programs, when completed boot to safe mode and run the removal tool for all versions of avast ever installed, reboot back to normal mode and install the newly saved avast from before.
