当安装vue-cli时，出现超时错误

npm ERR! code ECONNRESET npm ERR! network This is a problem related to network connectivity

npm ERR! code ECONNRESET
npm ERR! network aborted
npm ERR! network This is a problem related to network connectivity.
npm ERR! network In most cases you are behind a proxy or have bad network settings.
npm ERR! network
npm ERR! network If you are behind a proxy, please make sure that the
npm ERR! network 'proxy' config is set properly.  See: 'npm help config'; 

解决方法如下所示：

    1.在cmd终端输入以下命令，作用是设置代理
    npm config set proxy=

   2.然后使用淘宝镜像
 	npm config set registry https://registry.npm.taobao.org

    3.下载所需要的包
    npm install -g jquery

出现错误原因是：

1.代理设置有问题，没有相关代理的包；

2.重复安装导致网络阻塞；