Finding out which apps are using which ports on your machine

http://blogs.msdn.com/b/bgroth/archive/2004/11/11/256190.aspx

Above link suggests using "netstat" along with "tasklist"

Another way is to use "netstat" along with Task Manager

Step 1: Open Task Manager  -- select "View" -- select "Select Columns" -- check PID
Find out PID of the process whose port info you are after.

Step 2: (From above link)
C:\>NetStat -o

PID will displayed in the last column. Use PID from Step 1

Example: To find the port that "sqlservr.exe" is using, we first find out the PID from Task Manager ,which is 1660
If we now type "netstat -o" in a command prompt window, we will be able to see which port is being used by that PID ie 1660