To install Node.js on a Windows or Macintosh machine, go to the http://Nodejs.org website and click on the INSTALL button.
The browser will then ask you if you wish to download a file coming from the Nodejs.org website, to which you should agree.
Once the file is downloaded, execute it, launching a graphical installer as shown in the following screenshot:
When you click on Continue, the installer will prompt you to accept the Software License agreement.
If you agree with the terms, click on the Agree button (if you run a Mac OS) or check ...