异常：
0 info it worked if it ends with ok
1 verbose cli [ 'C:\Program Files (x86)\nodejs\\node.exe',
1 verbose cli 'C:\Program Files (x86)\nodejs\node_modules\npm\bin\npm-cli.js',
1 verbose cli 'install',
1 verbose cli 'express' ]
2 info using npm@2.7.4
3 info using node@v0.12.2
4 verbose node symlink C:Program Files (x86)
odejs\node.exe
5 silly cache add args [ 'express', null ]
6 verbose cache add spec express
7 silly cache add parsed spec { raw: 'express',
7 silly cache add scope: null,
7 silly cache add name: 'express',
7 silly cache add rawSpec: '',
7 silly cache add spec: '*',
7 silly cache add type: 'range' }
8 verbose addNamed express@*
9 silly addNamed semver.valid null
10 silly addNamed semver.validRange *
11 silly addNameRange { name: 'express', range: '*', hasData: false }
12 silly mapToRegistry name express
13 silly mapToRegistry using default registry
14 silly mapToRegistry registry https://registry.npmjs.org/
15 silly mapToRegistry uri https://registry.npmjs.org/express
16 verbose addNameRange registry:https://registry.npmjs.org/express not in flight; fetching
17 verbose request uri https://registry.npmjs.org/express
18 verbose request no auth needed
19 info attempt registry request try #1 at 09:48:35
20 verbose request id 4b1a32ff61036056
21 http request GET https://registry.npmjs.org/express
22 info retry will retry, error on last attempt: Error: connect ETIMEDOUT
23 info attempt registry request try #2 at 09:49:06
24 http request GET https://registry.npmjs.org/express
25 info retry will retry, error on last attempt: Error: connect ETIMEDOUT
26 info attempt registry request try #3 at 09:50:27
27 http request GET https://registry.npmjs.org/express
28 verbose stack Error: connect ETIMEDOUT
28 verbose stack at exports._errnoException (util.js:746:11)
28 verbose stack at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1000:19)
29 verbose cwd G:zhongshiyouITMSFileDownLoad
30 error Windows_NT 6.3.9600
31 error argv "C:\Program Files (x86)\nodejs\\node.exe" "C:\Program Files (x86)\nodejs\node_modules\npm\bin\npm-cli.js" "install" "express"
32 error node v0.12.2
33 error npm v2.7.4
34 error code ETIMEDOUT
35 error errno ETIMEDOUT
36 error syscall connect
37 error network connect ETIMEDOUT
37 error network This is most likely not a problem with npm itself
37 error network and is related to network connectivity.
37 error network In most cases you are behind a proxy or have bad network settings.
37 error network
37 error network If you are behind a proxy, please make sure that the
37 error network 'proxy' config is set properly. See: 'npm help config'
38 verbose exit [ 1, true ]
异常原因：
公司设置了上网代理，通过nmp安装express模块，代理错误
解决办法：
1，重新设置代理
http://manjeshpv.com/： npm config set proxy http://192.168.1.1:8080(代理服务器：端口)
npm config set https-proxy http://proxy-domain.com:8080 (代理服务器：端口)
2,选择http方式
npm config set registry=“http://registry.npmjs.org”//设置npm源地址
3,公司的网络可能需要验证http://www.cnblogs.com/chrischeng/archive/2013/03/22/2975235.html：
set http_proxy_user=username
set http_proxy_password=password
4，还有建议说将proxy set null
1.原npm地址
npm config set registry http://registry.npmjs.org
2.设置国内镜像
a.通过config命令
npm config set registry https://registry.npm.taobao.org npm info underscore （如果上面配置正确这个命令会有字符串response）
b.命令行指定
npm --registry https://registry.npm.taobao.org info underscore
c.编辑 ~/.npmrc 加入下面内容
registry = https://registry.npm.taobao.org
3.使用nrm管理registry地址
a.下载nrm
npm install -g nrm
b.添加registry地址
nrm add npm http://registry.npmjs.org
nrm add taobao https://registry.npm.taobao.org
c.切换npm registry地址
nrm use taobao
nrm use npm
搜索镜像: https://npm.taobao.org
建立或使用镜像,参考: https://github.com/cnpm/cnpmjs.org