Developed for Windows XP/Vista/2000 systems, BFilter is a freeware application that can be used to protect your system by blocking out pop-up banners and advertisements, which are often an annoyance and sometimes a malware. The application remains hidden in the right-hand tray and prevents pop-ups from appearing on your screen. This prevents the user from often clicking these windows, which is what downloads the virus or malware into your system. It does not download banners and therefore, these areas appear as blank spaces in your browser window. Its only limitation is that it does not allow users to selectively block banners in any site.