Check which application is using a port:

• Open the command prompt  and run netstat -aon | findstr \[port\_number\].
• If the port is being used by any application, then that application’s detail will be shown. The number, which is shown at the last column of the list, is the PID  (process ID) of that application. Make note of this.
• Type tasklist | findstr [PID]. Replace the [PID] with the number from the above step and hit enter.
• You’ll be shown the application name that is using your port number.

Checking which port is being used by a application:

• Open the command prompt and run tasklist | findstr [application_name]. Replace the [application_name] with the application that you want to check and hit enter.
• Make note of the PID (second column) from the details shown.
• Type netstat -aon | findstr \[PID\]. Replace the [PID] from the above step and hit enter.
• You’ll be shown the application detail and the corresponding port to which it is listening.