KillPopup - description from Softdepia.com:
KillPopup is a utility that automatically closes those anoying advertisement windows that some sites use. It is a small executable that runs in the task bar. When a popup window attempts to display, Killpopup quickly closes the window, often before it even becomes visible to the user. Right-clicking on the icon in the taskbar brings up options to temporarily suspend KillPopup or to quickly close all browser windows.
KillPopup is a "Free to try" program. You can download and try it for an evaluation period.