Mantra,
I don't think VLK understands which window you are referring too, but I think I do.
After an update, an "information" window opens and states "click here for more information"
Right!
Ok, firstly, don't bother to click on it because it won't take you anywhere. The Avast team put that feature in, but still are not sure what they want displayed when you do click on it. I am sure the next build will have it take you somewhere.
Anyway, open up the Avast anti-virus scanner.
Right click on the skin and go into Settings.
Under Settings, open Update, then click on Details.
When the iavs window opens, look for Running mode and click silent.
This should stop the alert window.
Good luck