I just installed Node.js and npm (for additional modules).
How can I update Node.js and the modules which I\'m using to the latest versions
Windows users should read Troubleshooting > Upgrading on Windows in the npm wiki.
The link above Troubleshooting#upgrading-on-windows points to a github page npm-windows-upgrade the lines below are quotes from the readme. I successfully upgraded from npm 2.7.4 to npm 3.9.3 using node v5.7.0 and powershell (presumably powershell version 5.0.10586.122)
First, ensure that you can execute scripts on your system by running the following command from an elevated PowerShell. To run PowerShell as Administrator, click Start, search for PowerShell, right-click PowerShell and select Run as Administrator.
Set-ExecutionPolicy Unrestricted -Scope CurrentUser -Force
Then, to install and use this upgrader tool, run (also from an elevated PowerShell or cmd.exe):
npm install --global --production npm-windows-upgrade
npm-windows-upgrade