- Download Ruby and install
 - Check ruby installation: ruby -e "puts 1+1" -> 2
 - irb - for interactive ruby commands
 - Download devkit for corresponding ruby version and extract to c:\devkit
 - Browse to c:\devkit and run this: ruby dk.rb init
 - type config.yml to see the location of all installed ruby version
 - Run ruby dk.rb install
 - gem install json --platform=ruby
 - check installation by running: ruby -rubygems -e "require 'json'; puts JSON.load('[42]').inspect"
 - gem -v
 - which gem
 - gem list
 - gem update --system -> to update all gems
 - gem install rails --version 4.0.0 --no-ri --no-rdoc or gem install rails -> for latest version