npm install without ssl

Try changing the registry to the http version rather that the default https one using the command

npm config set registry http://registry.npmjs.org/

As conlinf said, the following should work :

npm config set registry http://registry.npmjs.org/

Now, to add my word, you should also consider that downloading without ssl allows a man-in-the-middle attack. It is only to add a warning to people who would read the post.

If you are a solo developer there should be not much trouble downloading in http directly, but if I wanted to attack a company using node.js I would consider delivering malicious code through npm... And performing such an attack without ssl will be much easier.