C:\WINDOWS\system32>npm --registry=http://r.cnpmjs.org install cnpm -gnpm ERR! Windows_NT 6.2.9200npm ERR! argv "C:\\Program Files (x86)\\nodejs\\\\node.exe" "C:\\Program Files (x86)\\nodejs\\node_modules\\npm\\bin\\npm-cli.js" "--registry=http://r.cnpmjs.org" "install" "cnpm" "-g"npm ERR! node v0.12.0npm ERR! npm? v2.5.1npm ERR! code ETIMEDOUTnpm ERR! errno ETIMEDOUTnpm ERR! syscall connectnpm ERR! network connect ETIMEDOUTnpm ERR! network This is most likely not a problem with npm itselfnpm ERR! network and is related to network connectivity.npm ERR! network In most cases you are behind a proxy or have bad network settings.npm ERR! networknpm ERR! network If you are behind a proxy, please make sure that thenpm ERR! network 'proxy' config is set properly.? See: 'npm help config'npm ERR! Please include the following file with any support request:npm ERR!???? C:\WINDOWS\system32\npm-debug.log這是什么原因？？