During the NI Observer software installs a web server running HTTP traffic for web reporting functionality. This opens port 80 and starts pushing out HTTP traffic. There is a small green cog icon in the bottom right hand corner of the desktop (in the system tray) that can be right clicked. The pop up menu has an option to disable this. However, this does not block port 80 and leaves it open. NI has said to use Windows Firewall to block port 80 entirely if necessary.