Scenario:

When we install software which will use their default ports like IIS uses 80, FTP is 21 etc., we will see error like the ports are already being used by another application and we would not know which application actually using the ports. This doc is to find out which process/application is using which TCP port on windows.

Prerequisites:

1. Process explorer
2. Administrator privilege.

Steps:

1. Run this below command to find out the PID of the application which listens the port.
Example: netstat -ao | findstr :10200

2. Open Process explorer -> Sort the process by PID -> find out the Process which belongs to the PID. If this is a third party software you will get to know by the name but if it system related process/application you have to perform the step 3 and further.

3. Right click to the process -> Click Properties -> Go to Services tab
4. There you will find the service name.