This is very useful for people trying to run wamp or other web server on their PC windows, but encountered they cannot run or use port 80. Well it turns out some program already use that port and you just don’t know which one, or your software saying it’s Skype or some program that don’t even exist on your computer. Well here’s a sure way to find out.
1) Go to START–>Run and type cmd to bring up a Command prompt
2) In the Command Prompt window. type netstat -aon.
This will bring up a list of the ports and list what’s listening, established, starting, closing and all other states on them. In this example, look for the one ending in :80 (yes there’s a colon between the IP address and the port, so it may look something like 127.0.0.0:80).
3)To the right of the IP address ending in :80, you should see that the port is “listening”, and to the right of the listening state, there’s a PID (Process Identifier) number. Make a note of that number.Another method for finding out the port number is to download the fport utility:
Unzip it, place it in the root of c:\ , then in the command prompt window type in c:\fport. It will list out all the ports and what processes are using them. This is much faster to do and actually works better, as it identifies the program much more clearly.
4) Open up the Windows Task Manager (CTRL-ALT-DEL). In order to see the PID numbers of the various processes so you can identify which process is using Port 80, click on the Processes tab, then choose View–>Select Columns from the menu. Check the box next to PID (Process Identifier). You’ll now be able to see which process matches up with the PID number you noted earlier. If you used fport, you’ll already know which program it is.
Once I’d identified the process using port 80, I was able to close it down and save myself a lot of effort, and found I did not have to shut down my antivirus and other programs at all. And it saved me a lot of time trying to figure out what was causing the issue.