How to check which process using TCP/IP Ports in Windows

Run the following command from a command prompt to find the PID of the process which is using TCP port 80 and/or 443. 
   
    netstat -aon | find ":80" 
    netstat -aon | find ":443"

You will see an output similar to the following. Remember the actual PID will vary from case to case.
    TCP    0.0.0.0:80    0.0.0.0:0    LISTENING    3604 
    TCP    0.0.0.0:443   0.0.0.0:0    LISTENING    3320

Now using Task Manager you can easily find out to which process the above PID belongs and take appropriate action.

http://support.microsoft.com/kb/973094