NPM,从错误的URL地址下载依赖项

在处理某个项目后,我的npm开始从错误的全局地址下载依赖项:

npm install -g bower

npm ERR! code ETIMEDOUT
npm ERR! errno ETIMEDOUT
npm ERR! network request to http://172.168.1.1/bower failed, reason: 
    connect ETIMEDOUT 172.168.1.1
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'

npm ERR! A complete log of this run can be found in:

有没有办法将下载地址重置为默认地址?

我正在使用Windows版本的NodeJS