NPM has a bunch of useful stuff on it, however you could in life while using NPM get this:
stack Error: "pre" versions of node cannot be installed, use the --node dir flag instead
This error basically says “Give me the node directory because you I am a pre release version of node”
The simple way to fix this is just to get a version of node / npm that is stable. Etiher from you’re package manager or the online download.