node.js - How can install a new version of NPM ( 1.1.24 )? - Stack Overflow

Upgrading npm is rather easy. All it takes is

npm update npm -g

Source: node.js - How can install a new version of NPM ( 1.1.24 )? - Stack Overflow

Apparently, it should also be possible to upgrade Node itself, using NPM (link). However, this doesn't seem to work well on Windows.