TCPView is a
Windows program that 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.
On Windows NT, 2000 and XP TCPView 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. The TCPView
download includes Tcpvcon, a command-line version with
the same functionality.