Error: Port 4200 is already in use. Use ‘–port’ to specify a different port.

[Solution] For Windows, free up port 4200 by closing the Anjular program that is occupying port 4200

The first step is to type netstat -a -n -o in Terminal

Step 2: Find the port number 4200 and remember the corresponding PID

Step 3: In Terminal, type, taskkill -f /pid + the corresponding pid

https://stackoverflow.com/questions/39091735/port-4200-is-already-in-use-when-running-the-ng-serve-command