node Error: failed to fetch from registry: express

i'm quite new to node. trying to installing node.js on the AWS getting error while running this command

sudo npm install express -g.

going with the process given here

http://ift.tt/xDwEm3

![enter image description here][1]

attached screen short below.

[1]: ht tp://i.stack.imgur.com/Eebsj.png