You could run  npm i -g npm to update your node, but you should go for:

1. Open a Powershell as Administrator
2. Set the Execution Policy the right way, with unrestricted rights:
   Set-ExecutionPolicy Unrestricted -Scope CurrentUser -Force

   1	Set-ExecutionPolicy Unrestricted -Scope CurrentUser -Force

    
3. Install the npm-windows-upgrade package as global:
   npm install -g npm-windows-upgrade

   1	npm install -g npm-windows-upgrade

4. Finally, run the updater and choose your desired version:
   npm-windows-upgrade

   1	npm-windows-upgrade

Upgrade node on Windows

 

According to stack overflow user „Robert“, here are the reasons for updating NPM the way described here:

• Upgrades npm in-place, where node installed it.
• Easy updating, update the to the latest by running
  npm-windows-upgrade -p -v latest

  1	npm-windows-upgrade -p -v latest

  .
• Does not modify the default path.
• Does not change the default global package location.
• Allows easy upgrades and downgrades.
• Officially recommended by the NPM team.