由於環境變量的問題導致react項目不能運行的解決辦法

　　首先來看下cmd的報錯

$ react-scripts startStarting the development server...

events.js:292

  throw er; // Unhandled 'error' event
 ^

Error: spawn powershell ENOENT

at Process.ChildProcess._handle.onexit (internal/child_process.js:267:19)
at onErrorNT (internal/child_process.js:469:16)
at processTicksAndRejections (internal/process/task_queues.js:84:21)

Emitted 'error' event on ChildProcess instance at:

at Process.ChildProcess._handle.onexit (internal/child_process.js:273:12)
at onErrorNT (internal/child_process.js:469:16)
at processTicksAndRejections (internal/process/task_queues.js:84:21) {

errno: 'ENOENT', code: 'ENOENT', syscall: 'spawn powershell', path: 'powershell', spawnargs: [

'-NoProfile',
'-NonInteractive',
'每ExecutionPolicy',
'Bypass',
'-EncodedCommand',
'UwB0AGEAcgB0ACAAIgBgACIAaAB0AHQAcAA6AC8ALwBsAG8AYwBhAGwAaABvAHMAdAA6ADMAMAA

wADAAYAAiACIA' ]}error Command failed with exit code 1.info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

標紅的這句可以看到，他說沒有這樣的文件目錄（就是powershell不存在）

解決辦法就是修改系統的環境變量，編輯系統變量末尾記得添加英文分號再加上C:\Windows\System32\WindowsPowerShell\v1.0      這句話就可以正常運行了