free popup blocker

Browser built-in popup blockers are limited in effectiveness. They typically don't block Javascript based popups. Try this Simple Popup Test. Most browsers won't block it? Some may prompt you with warning such as IE, depending on configuration?

As mentioned, you may need to incorporate an ad blocking extension in your browser. Plus a separate Javascript blocking add-on. Of course, you can manually disable Javascript, but can become tedious as many websites require it to work.