This is the error while I'm running from Node.js Command prompt:

This is the error while I'm running from power shell or CMD:

This is the error file from power shell while command - "node myfirst.js":

Code:
var http = require('https');
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/html'});
res.end('Hello World!');
}).listen(8080);
Error:
asd.js : The term 'asd.js' is not recognized as the name of a cmdlet, function, script file,
or operable program.
Check the spelling of the name, or if a path was included, verify that the path is correct and
try again.
At line:1 char:1
+ asd.js
+ ~~~~~~
+ Category Info : ObjectNotFound: (asd.js:String) [], CommandNotFoundException
+ FullyQualifiedErrorId : CommandNotFoundException
To run your node.js script, type node <filename>, in your case: node ast.js.
The error https://i.stack.imgur.com/llqlm.png indicates that there's a port conflict, another process already uses 8080 port.
To fix it, kill the process who uses 8080 port, or just use another port:
var http = require('https');
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/html'});
res.end('Hello World!');
}).listen(9999); // another port