ionic cli: all commands giving error undefined:1 SyntaxError: Unexpected token

I have downloaded and installed nodejs (setup file node-v0.12.5-x64) in my Windows7 pc.
Also installed ionic via command: npm install -g ionic cordova

All ionic commands are giving same error i.e. undefined:1.
In command prompt it looks like below:

E:\programs>ionic -v  
undefined:1  
SyntaxError: Unexpected token

I am not able to resolve after many installation and un-installation.
Please help.