node.js – 节点找不到快递模块？

C:\Users\phucker\Desktop>node init.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.<anonymous> (C:\Users\phucker\Desktop\init.js:1:77)
    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)

C:\Users\phucker\Desktop>npm express -v
1.3.2

C:\Users\phucker\Desktop>

init.js中包含的代码是

var express = require('express');
var app = express();

app.get('/',function(req,res){
  res.send('Hello world');
});

app.listen(3000);