There are 2 parts of the NODEJS Windows installer.
1. NODE.exe
First, You need download the binary (.exe) from
http://nodejs.org/dist/latest/ and save it to your local folder. (For x64:
http://nodejs.org/dist/latest/x64/ )
Second, add your local folder to your PATH Environment.
2. NPM
First, downloads the NPM from
http://nodejs.org/dist/npm/ (You can select a stable version in this folder. )
Second, extract the .zip/.tgz to your local folder and add this folder to you PATH Environment.