Finding application that is utilizing which network port
Ever encounter the situation where you need to find out which application is currently utilizing the port. You can do this with just tools that came with Microsoft Windows.
Open the command prompt and issue the netstat command
Start > Run > cmd > netstat -ano
Then you would see the ports being used and the Process ID (PID) associated to it
Open the Task Manager and match the PID to the application which is using it. The PID column might not be visible by default, you can enable the column by
Windows Task Manager > View > Select Columns… > PID (Process Identifier) > OK
After Windows XP SP2, the command line parameter -b was which displays the executable involved in creating each connection or listening port. In some cases well-known executables host multiple independent components, and in these cases the sequence of components involved in creating the connection or listening port is displayed. In this case the executable name is in  at the bottom, on top is the component it called, and so forth until TCP/IP was reached. Note that this option can be time-consuming and will fail unless you have sufficient permissions.
Start > Run > cmd > netstat -anob
Microsoft Netstat : [LINK]