Node.js/Windows error: ENOENT, stat 'C:\Users\RT\AppData\Roaming\npm'

I recommend setting an alternative location for your npm modules.

npm config set prefix C:\Dev\npm-repository\npm --global 
npm config set cache C:\Dev\npm-repository\npm-cache --global  

Of course you can set the location to wherever best suits.

This has worked well for me and gets around any permissions issues that you may encounter.

Manually creating a folder named 'npm' in the displayed path fixed the problem.

More information can be found on Troubleshooting page

This can also be fixed by installing a node package manually.

npm install npm -g

The process of doing that will setup all the required directories.

I ran into the same problem while installing a package via npm.

After creating the npm folder manually in C:\Users\UserName\AppData\Roaming\ that particular error was gone, but it gave similar multiple errors as it tried to create additional directories in the npm folder and failed. The issue was resolved after running the command prompt as an administrator.