I downloaded the sdk (3.0a1). According to cocos2d-x guide, I have to run the create-multi-platform-projects.py
command in order to create a project, but the script doesn't exist in the package I have downloaded.
The guide says
Note: These instructions are only valid for cocos2d-x v3.0-alpha0 or newer
So I suppose that I have downloaded the right package (windows 8.0 64bit).