报错：
e:\StudyFile\kaikeba\works\React专题\react-router>npm start
> react-router@0.1.0 start e:\StudyFile\kaikeba\works\React专题\react-router
> react-scripts start
Starting the development server...
events.js:288
throw er; // Unhandled 'error' event
^
Error: spawn cmd ENOENT
?[90m at Process.ChildProcess._handle.onexit (internal/child_process.js:267:19)?[39m
?[90m at onErrorNT (internal/child_process.js:469:16)?[39m
?[90m at processTicksAndRejections (internal/process/task_queues.js:84:21)?[39m
Emitted 'error' event on ChildProcess instance at:
?[90m at Process.ChildProcess._handle.onexit (internal/child_process.js:273:12)?[39m
?[90m at onErrorNT (internal/child_process.js:469:16)?[39m
?[90m at processTicksAndRejections (internal/process/task_queues.js:84:21)?[39m {
errno: ?[32m'ENOENT'?[39m,
code: ?[32m'ENOENT'?[39m,
syscall: ?[32m'spawn cmd'?[39m,
path: ?[32m'cmd'?[39m,
spawnargs: [ ?[32m'/s'?[39m, ?[32m'/c'?[39m, ?[32m'start'?[39m, ?[32m'""'?[39m, ?[32m'/b'?[39m, ?[32m'"http://localhost:3000"'?[39m ]
}
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! react-router@0.1.0 start: `react-scripts start`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the react-router@0.1.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR! D:\NodeJs\node_cache\_logs\2020-04-03T08_59_34_174Z-debug.log
问题原因：电脑使用的不是admin用户，不能直接读取路径C:\Windows\System32（netstat -ano这些命令都不可用，只能以管理员身份登录才能用），所以问题在于用户权限问题。
解决：在环境变量中path中加上 ;C:\Windows\System32 即可