Port 80 is being used by SYSTEM (PID 4), what is that?

I am trying to use port 80 for my application server, but when I perform netstat -aon I get:

TCP 0.0.0.0:80 0.0.0.0:0 LISTENING 4

When I look up the process in task manager, it shows PID 4 is SYSTEM, that's it. No extension... nothing. Just "SYSTEM". What's going on here?

I'm afraid to end this process, what do I do?

the IP adress is 0.0.0.0, state = LISTENING: means that port 80 is listening to all interfaces (not used)

How to read NETSTAT -AN results:

• https://sites.google.com/site/xiangyangsite/home/technical-tips/linux-unix/networks-related-commands-on-linux/how-to-read-netstat--an-results