I guess you wanted to write “…not showing…” in your first post.

In the Professional version of avast!, it is possible - you can configure the automatic action to be performed with infected files (and the action can also be “nothing”).
In the Home version of avast!, there is no such option directly; when the first virus is detected, you can check the “Don’t show this window next time” option in the virus dialog and you’ll get the report in the end.