title: Unable to execute child_process.exec("node child.js")
body: <p>I have two files under a folder with names "app.js" and "child.js". The Node is running on Windows OS.
  The app.js file:</p>
  
  <pre><code>;(function() {
      var http = require("http"),
      child_process = require("child_process"),
      exec = child_process.exec;
  
      http.createServer(function(request, response) {
          response.writeHead(200, {"content-type": "text/plain"});
          exec('node child.js', {env: {number: 1234}}, function(error, stdout, stderror) {
              if(error) throw error;
              console.log(stdout);
              console.log(stderror);
          });
          response.write("Hello world!!!");
          response.end();
      }).listen(8000);
      console.log("The server has started listening to the port: 8000");
  })();  
  </code></pre>
  
  <p>The child.js file:</p>
  
  <pre><code>;(function() {
      var envVar = process.env.envVar;
      console.log("Type of envVar: " + typeof envVar);
      console.log("The value of envVar is: " + parseInt(envVar, 10));
  })();
  </code></pre>
  
  <p>I am attempting to execute an external command via "exec" method.<br>
  But when I run:  </p>
  
  <pre><code>node app.js  
  </code></pre>
  
  <p>I receive the error:</p>
  
  <pre><code>Command failed: 'node' is not recognized as an internal or external command, operable program or batch file.  
  </code></pre>
  
  <p>What wrong am I doing here?</p>