win7 64位安装yeoman报错

在安装yeoman,出现以下错误，小白一个，求大神指导，查了资料但是我的问题没有解决，求大神看一下问题

$ npm install -g yo
npm WARN deprecated npmconf@2.1.2: this package has been reintegrated into npm and is now out of date with respect to npm
C:\Users\sxm\AppData\Roaming\npm\yo-complete -> C:\Users\sxm\AppData\Roaming\npm\node_modules\yo\lib\completion\index.js
npm ERR! Windows_NT 6.1.7601
npm ERR! argv "C:\\Program Files\\nodejs\\node.exe" "C:\\Users\\sxm\\AppData\\Roaming\\npm\\node_modules\\npm\\bin\\npm-cli.js" "install" "-g" "yo"
npm ERR! node v6.4.0
npm ERR! npm  v3.10.6
npm ERR! path C:\Users\sxm\AppData\Roaming\npm\yo
npm ERR! code EPERM
npm ERR! errno -4048
npm ERR! syscall open
 
npm ERR! Error: EPERM: operation not permitted, open 'C:\Users\sxm\AppData\Roaming\npm\yo'
npm ERR!     at Error (native)
npm ERR!  { Error: EPERM: operation not permitted, open 'C:\Users\sxm\AppData\Roaming\npm\yo'
npm ERR!     at Error (native)
npm ERR!   errno: -4048,
npm ERR!   code: 'EPERM',
npm ERR!   syscall: 'open',
npm ERR!   path: 'C:\\Users\\sxm\\AppData\\Roaming\\npm\\yo' }
npm ERR!
npm ERR! Please try running this command again as root/Administrator.
 
npm ERR! Please include the following file with any support request:
npm ERR!     D:\workspace\npm-debug.log

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window系统好多奇怪的问题,安装linux系统基本没毛病