It works fully automatic and in the background and the only way to notice that a popup window has been closed, is if you choose to activate the sound notification which will sound every time a popup is closed.

Main Popup Assassin Pro features: - Popup Assassin Pro is very fast and small; - Works best at blocking popup ads when using Internet Explorer; - Kills unwanted popup ads before they open; - Configure sites to block; - Allows to open any killed window from Popup Assassin Pro log; - Play different sounds when ads are blocked; - Runs in the system Tray.

This prevents popup ads from stealing bandwidth or locking up your browser with multiple windows opening.