Find PID of process that use a port on Windows (e.g. port:"8080")

Fire the below comands via Command Line Interface

netstat -a -o -n | findstr 0.0:8080

-a Displays all connections and listening ports.

-o Displays the owning process ID associated with each connection.

-n Displays addresses and port numbers in numerical form.

Output
TCP 0.0.0.0:8080 0.0.0.0:0 LISTENING 6800

Then Kill the process by PID

taskkill /F /PID 6800

/F - Specifies to forcefully terminate the process(es).