ExpressJS - Not able to create Basic App

I installed the express - using npm -g express, And the express is installed globally. which is available on my system in the path of C:\Users\xxxxx\AppData\Roaming\npm\node_modules.

Later I try to create a Basic App, using express in the command of express myApp ( after I mapped a sampleFolder, But the express is not providing any basic app settings.

Instead, it throws the error as :

D:\Tutorials\Angular\Projects - Angular\NG-SERVER>express myApp
'express' is not recognized as an internal or external command,
operable program or batch file.

What is the thing which i do incorrect here? any one help me to create express basic app please?

I am using Windows7 here.

Thanks In advance!