Fameous ENOENT problem:
'Error: ENOENT, stat 'C:\Users\username\AppData\Local\npm',
A lot of accepted solutions around the net say that you should try to manually create the npm folder. And It works. But my problem was a little bit different. I was forced to set up external folder for node_modules. I set up it wrong ( :D ) with some '' around the path and this was a mistake cause whole npm was broken.
To fix it I was searching for a file with this configuration and finally I succeed:
If You set it globally or in root of npm installation
Hope It will save some time for somebody...