Grunt is not recognised : windows7 64-bit

I have installed npm and installed grunt, but when i run grunt, it says 'grunt' is not recognized as an internal or external command.

I done the below steps in command prompt

npm install

npm install -g grunt-cli

PATH variable and grunt folder are available but still i am not able to run grunt. Please provide me a solution for this

You have only installed the command line interface.

Use npm install -g grunt to install the actual program.