如果用npm start就报错

npm ERR! Windows_NT 10.0.14393
npm ERR! argv "C:\\Program Files\\nodejs\\node.exe" "C:\\Users\\B\\AppData\\Roaming\\npm\\node_modules\\npm\\bin\\npm-cli.js" "start"
npm ERR! node v7.6.0
npm ERR! npm  v4.3.0
npm ERR! path C:\WINDOWS\system32\package.json
npm ERR! code ENOENT
npm ERR! errno -4058
npm ERR! syscall open

npm ERR! enoent ENOENT: no such file or directory, open 'C:\WINDOWS\system32\package.json'
npm ERR! enoent ENOENT: no such file or directory, open 'C:\WINDOWS\system32\package.json'
npm ERR! enoent This is most likely not a problem with npm itself
npm ERR! enoent and is related to npm not being able to find a file.
npm ERR! enoent

npm ERR! Please include the following file with any support request:
npm ERR!     C:\Users\B\AppData\Roaming\npm-cache\_logs\2017-03-13T06_32_17_024Z-debug.log

如果是$npm start就说'$npm' 不是内部或外部命令，也不是可运行的程序
或批处理文件。