我在react-native上有一个错误：spawn cmd ENOENT

Question

我正在使用expo cli开发一个本机应用程序，但是当我执行expo start时出现此错误：

Error: spawn cmd ENOENT
    at Process.ChildProcess._handle.onexit (internal/child_process.js:232:19)
    at onErrorNT (internal/child_process.js:407:16)
    at process._tickCallback (internal/process/next_tick.js:63:19)

我已经重新安装了expo cli

    {
  "main": "node_modules/expo/AppEntry.js",
  "scripts": {
    "start": "expo start",
    "android": "expo start --android",
    "ios": "expo start --ios",
    "eject": "expo eject"
  },
  "dependencies": {
    "expo": "^31.0.0",
    "react": "16.5.0",
    "react-native": "https://github.com/expo/react-native/archive/sdk-31.0.0.tar.gz"
  },
  "devDependencies": {
    "babel-preset-expo": "^5.0.0",
    "expo-cli": "^2.7.0"
  },
  "private": true
}

我想用genymotion模拟这个应用程序