I just downloaded node but npm is not working. whenever I use a npm comman I get Error: cannot find module \'strip-ansi\'.
I hit this same issue. I tried to update npm after a fresh Node.js install, but cancelled in the middle because it appeared stuck. Reinstalling Node.js didn't help.
I resolved the issue by deleting the temporary npm files in my AppData folder (for me on Windows, I found it in c:\Users\Me\AppData\Roaming\npm). Then I was able to run npm normally again.
Hope that helps!