Install Cygwin (http://www.cygwin.com/)
- Select the folowing packages: curl, git, nano, openssh, openssl, ruby, unzip, util-linux, vim, wget
Download the RubyGems tarball from Ruby Forge (https://rubygems.org/pages/download)
- wget http://production.cf.rubygems.org/rubygems/rubygems-2.2.2.zip
- unzip rubygems-2.2.2.zip
In a bash terminal, navigate to the unpacked directory and run: