Node.js with express - npm start do not work

I have problem trying to run node app in Windows 7.I have installed express generator globally and with it help created a test_app directory and installed the modules. In the package.json scripts look like this:

"scripts": {
    "start": "node ./bin/www"
  }

However, when i run npm start it just returns this in console:

test_app@0.0.1 start C:\work\test_app
node ./bin/www

If i try to run node app.js nothing happens. Before there wasn't problems with the express, until the moment when i had to install express-generate globally.