Unable to install Ember.js

I am trying to install Ember CLI but I am getting error, I am not getting what exactly I need to do.

I am running the below command to install Ember CLI in my C drive:

npm install -g ember-cli

I am getting the below error:

npm ERR! Windows_NT 6.1.7601
npm ERR! argv "C:\\Program Files\\nodejs\\\\node.exe" "C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js" "install" "-g" "ember-cli"
npm ERR! node v0.12.5
npm ERR! npm  v2.11.2
npm ERR! code ETIMEDOUT
npm ERR! errno ETIMEDOUT
npm ERR! syscall connect

npm ERR! network connect ETIMEDOUT
npm ERR! network This is most likely not a problem with npm itself
npm 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! 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! Windows_NT 6.1.7601
npm ERR! argv "C:\\Program Files\\nodejs\\\\node.exe" "C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js" "install" "-g" "ember-cli"
npm ERR! node v0.12.5
npm ERR! npm  v2.11.2
npm ERR! path C:\npm-debug.log.9900b075918cf81d21ff4fa7a56e3bc6
npm ERR! code EPERM
npm ERR! errno -4048

npm ERR! Error: EPERM, open 'C:\npm-debug.log.9900b075918cf81d21ff4fa7a56e3bc6'
npm ERR!     at Error (native)
npm ERR!  { [Error: EPERM, open 'C:\npm-debug.log.9900b075918cf81d21ff4fa7a56e3bc6']
npm ERR!   errno: -4048,
npm ERR!   code: 'EPERM',
npm ERR!   path: 'C:\\npm-debug.log.9900b075918cf81d21ff4fa7a56e3bc6' }
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!     C:\npm-debug.log