Fix Xamp (Port 80 in use by "Unable to open process" with PID 4)

Open a CMD prompt and type in command: net stop was /y


    Run Dialog Box (press keys Win+R) .. then type: services.msc

I then scrolled down to: World Wide Web Publishing Service Double clicked on it and clicked STOP (if this service status is Started)

3.Start Apache again with XAMPP :)