TCPView is a free portable application from Microsoft Sysinternals team which will show you detailed listings of all TCP and UDP endpoints on your system, including the local and remote addresses and state of TCP connections. The application also reports the name of the process that owns the endpoint. TCPView provides a more informative and conveniently presented subset of the Netstat program that ships with Windows.
When you download TCPView, it also includes Tcpvcon, a command-line version with the same functionality. When you start TCPView it will enumerate all active TCP and UDP endpoints, resolving all IP addresses to their domain name versions. You can use a toolbar button or menu item to toggle the display of resolved names.
You can close established TCP/IP connections by selecting Close Connections from the file menu, or by right-clicking on a connection and choosing Close Connections from the context menu.
