For people who work in a company and squeez out some of their time to learn nodejs, setting up an dev-environment can be a real pain. Proxy servers are pretty common in college and business type institutions.
You can locate your proxy settings from your browser's settings panel.
Using Proxy with NPM
Once you have obtained the proxy settings (server URL, port, username and password); you need to configure your npm configurations as follows.
npm config set proxy http://<username>:<password>@<proxy-server-url>:<port> npm config set https-proxy http://<username>:<password>@<proxy-server-url>:<port>
You would have to replace
<port> with the values specific to your proxy server credentials.
These fields are optional. For instance, your proxy server might not even require
<password>, or that it might be running on port 80 (in which case
<port> is not required).
Once you have set these, your npm install,
npm i -g etc. would work properly.