npm安装错误角度2

Question

安装Angular2时出现此错误

npm ERR! Windows_NT 10.0.14393
npm ERR! argv "C:\\Program Files\\nodejs\\node.exe" "C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js" "install" "-g" "angular-cli"
npm ERR! node v7.4.0
npm ERR! npm  v4.0.5

npm ERR! Cannot read property 'path' of null
npm ERR!
npm ERR! If you need help, you may report this error at:
npm ERR!     <https://github.com/npm/npm/issues>

npm ERR! Please include the following file with any support request:
npm ERR!     C:\angular2-demo\npm-debug.log

如何解决这个问题