How can I reset my NPM config file?

So I'm pretty tangled up here. Basically I was trying to do a global Bower install on Windows

npm install bower -g 

my Git Bash kept saying the bash command was not found, although bower was successfully installed.

Then someone suggested that the file path might be different, and change the prefix as so:

npm config set prefix /usr/local

Turns out this is not a solution for Windows. So I ended up with the same exact problem here

Error: EPERM: operation not permitted, mkdir 'C:\Program Files (x86)\Git\local'
at Error (native)

Now when I try any NPM command, the CLI just hangs there! Is here a simple way to just nuke all this and start from the beginning. A simple uninstall and reinstall of Node doesn't do the trick.

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