FPort: Lists open TCP ports and their associated applications
Many have had this problem: One installs a new internet application on a server but when it is started you get a message like "port already in use". Now it's time for a port mapper, an application that lists open TCP ports and their associated applications
FPort reports all open TCP/IP and UDP ports and maps them to the owning application. This is the same information you would see using the 'netstat -an' command, but it also maps those ports to running processes with the PID, process name and path. FPort can be used to quickly identify unknown open ports and their associated applications.
FPort officially supports Windows NT4, Windows 2000 and Windows XP.
Download it here (Freeware):
As an alternative, execute the following command in the command line tool:
netstat -an -b