How Can I Tell What is Listening on a TCP/IP Port in Windows?

Open up a command prompt and type in the following—you may have to open in Administrator mode to see all processes:

netstat -ab | more
a
b
c  
  

This will immediately show you a list, although it’s maybe a little complicated. You’ll see the process name in the list, and you can search for it.

You can also use this other method, which takes an extra step, but makes it easier to locate the actual process:

netstat -aon | more

If you look on the right-hand side, you’ll see where I’ve highlighted the list of PIDs, or Process Identifiers. Find the one that’s bound to the port that you’re trying to troubleshoot—for this example, you’ll see that 0.0.0.0:80, or port 80, is in use by PID 4708.

Now you can simply open up Task Manager—you might have to use the option to Show Processes for All Users, and then you’ll be able to find the PID in the list. Once you’re there, you can use the End Process, Open File Location, or Go to Service(s) options to control the process or stop it.

You can also use CurrPorts to directly kill the process if you want.
Download CurrPorts from nirsoft.net