The best way would have been not to have enabled them as they are disabled by default, if what you are describing is what I think it is.
Standard Shield, Customize, Advanced - 'Show detailed info on performed actions' this option is off by default, so it would appear you have been tweaking avast without knowing the effect it will have.
This function is also on the Web Shield and Internet Mail providers so you should also check those.
avast isn't a blocker it scans and alerts to infection, so are you saying an application installer is reported as infected ?
Can you explain in more detail how you blocked it ?