title: Node js express is installed however still throwing not found error
body: <p>i have installed <code>express</code> using:</p>
  
  <pre><code>npm install express -g
  </code></pre>
  
  <p>Now when i call: </p>
  
  <p><code>npm install express
  </code></p>
  
  <p>i get the following result:</p>
  
  <pre><code>    /home/marc/node
  └── express@4.11.1 
  </code></pre>
  
  <p>So when i want to run my hello world script:</p>
  
  <pre><code>    var express = require('express');
  var app = express();
  app.get('/', function(req, res){
      res.send('Hello World');
  });
  
  app.listen(3000);
  </code></pre>
  
  <p>i still get the following error:</p>
  
  <pre><code>    Marc node # node /home/marc/nodejstest/server.js
  
  module.js:340
      throw err;
            ^
  Error: Cannot find module 'express'
      at Function.Module._resolveFilename (module.js:338:15)
      at Function.Module._load (module.js:280:25)
      at Module.require (module.js:364:17)
      at require (module.js:380:17)
      at Object.&lt;anonymous&gt; (/home/marc/nodejstest/server.js:8:15)
      at Module._compile (module.js:456:26)
      at Object.Module._extensions..js (module.js:474:10)
      at Module.load (module.js:356:32)
      at Function.Module._load (module.js:312:12)
      at Function.Module.runMain (module.js:497:10)
  </code></pre>
  
  <p>Can anyone tell me what might be the problem here?</p>
  
  <p>my npm list:</p>
  
  <pre><code>    Marc node # npm list
  /home/marc/node
  └─┬ express@4.11.1
    ├─┬ accepts@1.2.2
    │ ├─┬ mime-types@2.0.7
    │ │ └── mime-db@1.5.0
    │ └── negotiator@0.5.0
    ├── content-disposition@0.5.0
    ├── cookie@0.1.2
    ├── cookie-signature@1.0.5
    ├─┬ debug@2.1.1
    │ └── ms@0.6.2
    ├── depd@1.0.0
    ├── escape-html@1.0.1
    ├─┬ etag@1.5.1
    │ └── crc@3.2.1
    ├── finalhandler@0.3.3
    ├── fresh@0.2.4
    ├── media-typer@0.3.0
    ├── merge-descriptors@0.0.2
    ├── methods@1.1.1
    ├─┬ on-finished@2.2.0
    │ └── ee-first@1.1.0
    ├── parseurl@1.3.0
    ├── path-to-regexp@0.1.3
    ├─┬ proxy-addr@1.0.5
    │ ├── forwarded@0.1.0
    │ └── ipaddr.js@0.1.6
    ├── qs@2.3.3
    ├── range-parser@1.0.2
    ├─┬ send@0.11.1
    │ ├── destroy@1.0.3
    │ ├── mime@1.2.11
    │ └── ms@0.7.0
    ├── serve-static@1.8.1
    ├─┬ type-is@1.5.5
    │ └─┬ mime-types@2.0.7
    │   └── mime-db@1.5.0
    ├── utils-merge@1.0.0
    └── vary@1.0.0
  </code></pre>