Today, I got a request from an application team stating that there application is not running. When checked found that there application is configured on port 80. Later, found that port 80 was not free and could see that port 80 was already listening with the process id (PID) 4, to my surprise, PID 4 is “NT Kernel & System” Owner SYSTEM

Command used to find the port 80 details:

netstat -aon | findstr 80

it will show you all processes that use port 80.

Finally, I was able to fix the issue by stopping the world wide web publishing service in the service manager.

There was no need for the IIS by the application team. Hence, I set the WWW publishing service as manual.

This fixed the issue and we tested by rebooting the server again.

Thanks,
WintelAdmin