nodejs 340 error: cannot find module

I installed node.js on a windows 7 ultimate machine.

Created a hello world program with one line
console.log('hello world');
saved it into the same folder as installation.
went to that folder in command prompt
and tried to execute the file using
node hello.js
It is giving error

c:\Program Files\nodejs>node hello.js

module.js:340
throw err;
^

I have read all the answers for same question asked ,none of them worked for me.

how can I solve this issue?