now I am trying to install bcrypt in windows 10, but I got an loading error whenever running webrick server as the following.
C:/Ruby22-x64/lib/ruby/gems/2.2
In your gem file add:
gem 'bcrypt', git: 'https://github.com/codahale/bcrypt-ruby.git', :require => 'bcrypt'
This worked for me on Windows 10 64 Bit.