title: npm.cmd closes instantly after few seconds
body: <p>I'm learning nodeJs. I managed to run nodejs commands on cmd and it works fine. Now I want to install express framework and for that in the tutorial I'm following it asks to type <code>sudo install -g express</code> on npm command prompt. So I typed npm in my windows search, and clicked on it. Right after few seconds less  than 3 it closes straight away. </p>
  
  <p>I found that npm.cmd exist in nodejs directory where node.exe found. What could be the problem here. If I were to type the above mentioned command in windows cmd, it says sudo is unrecognized program.SO must I use npm cmd?</p>