"NODE_ENV" is not recognized as an internal or external command, operable command or batch file

I'm trying to setup an environment for a Node.js app. but I'm getting this error every time.

"NODE_ENV" is not recognized as an internal or external command, operable command or batch file.

What does this mean and how can I solve this problem?

I'm using Windows and also tried set NODE_ENV=development but had no luck.

I wrote a module for this: win-node-env.

It creates a NODE_ENV.cmd that sets the NODE_ENV environment variable and spawns a child process with the rest of the command and its args.

Just install it (globally), and run your npm script commands, it should automatically make them work.

npm install -g win-node-env

It sounds like your error comes from an attempt to run something like this (which works in Linux)

NODE_ENV=development node foo.js

the equivalent in Windows would be

SET NODE_ENV=development
node foo.js

running in the same command shell. You mentioned set NODE_ENV did not work, but wasn't clear how/when you executed it.

for windows use & in between command also. Like,

  "scripts": {
    "start": "SET NODE_ENV=development & nodemon app/app.js",
  }

1. npm install --save-dev "cross-env" module.
2. modify the code as cross-env NODE_ENV=development node foo.js. Then you can run the like npm run build.

Use win-node-env, For using it just run below command on your cmd or power shell or git bash:

npm install -g win-node-env

After it everything is like Linux.