From NirSoft Freeware:
CurrPorts will display the list of all currently opened TCP/IP and UDP ports on your PC. For each port in the list, information about the process that opened the port is also displayed, including the process name, full path of the process, version information of the process (product name, file description), the time that the process was created, and the user that created it. It allows you to close unwanted TCP connections, kill the process that opened the ports, and save the TCP/UDP ports information to HTML file, XML file, or to tab-delimited text file. CurrPorts also automatically mark with pink color suspicious TCP/UDP ports owned by unidentified applications.
What's new in this version:
Version 2.12 is a bug fixing release.