1. in Windows 10, enable Developer Mode, let it install
2. in the Programs and Features menu, open Turn Windows Features On or Off, scroll to the very bottom, choose Windows Subsystem for Linux, run the installation and let the computer restart
3. after the restart, run bash in the Start menu as admin
4. create a Unix username and password
5. press the Y key and let the Ubuntu base be installed

sudo apt-get install ruby2.0 ruby2.0-dev libssl-dev make g++

sudo rm /usr/bin/ruby /usr/bin/gem /usr/bin/irb /usr/bin/rdoc /usr/bin/erb
sudo ln -s /usr/bin/ruby2.0 /usr/bin/ruby
sudo ln -s /usr/bin/gem2.0 /usr/bin/gem
sudo ln -s /usr/bin/irb2.0 /usr/bin/irb
sudo ln -s /usr/bin/rdoc2.0 /usr/bin/rdoc
sudo ln -s /usr/bin/erb2.0 /usr/bin/erb
sudo gem update --system
sudo gem pristine --all

Source: http://blog.costan.us/2014/04/restoring-ruby-20-on-ubuntu-1404.html