mysql - Ruby/Sinatra Data_Mapper の問題

Question

Ruby/Sinatra をいじっていて、data_mapper を MySQL で動作させようとしていましたが、Sinatra アプリを実行しようとすると、このエラーが発生します。私はRubyの世界に慣れていないので、どんなガイダンスも大歓迎です。

C:/RailsInstaller/Ruby1.9.3/lib/ruby/site_ruby/1.9.1/rubygems/core_ext/kernel_require.rb:45:in `require': 126: The speci fied module could not be found.   - C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/do_mysql-0.10.12-x86-mingw32/li b/do_mysql/1.9/do_mysql.so (LoadError)
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/site_ruby/1.9.1/rubygems/core_ext/kernel_require.rb:45:in `require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/do_mysql-0.10.12-x86-mingw32/lib/do_mysql.rb:33:in `re scue in <top (required)>'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/do_mysql-0.10.12-x86-mingw32/lib/do_mysql.rb:28:in `<t op (required)>'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/site_ruby/1.9.1/rubygems/core_ext/kernel_require.rb:45:in `require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/site_ruby/1.9.1/rubygems/core_ext/kernel_require.rb:45:in `require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/dm-mysql-adapter-1.2.0/lib/dm-mysql-adapter/adapter.rb :1:in `<top (required)>'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/site_ruby/1.9.1/rubygems/core_ext/kernel_require.rb:45:in `require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/site_ruby/1.9.1/rubygems/core_ext/kernel_require.rb:45:in `require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/dm-mysql-adapter-1.2.0/lib/dm-mysql-adapter.rb:1:in `< top (required)>'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/site_ruby/1.9.1/rubygems/core_ext/kernel_require.rb:110:in `require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/site_ruby/1.9.1/rubygems/core_ext/kernel_require.rb:110:in `rescue in require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/site_ruby/1.9.1/rubygems/core_ext/kernel_require.rb:35:in `require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/dm-core-1.2.0/lib/dm-core/adapters.rb:163:in `load_ada pter'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/dm-core-1.2.0/lib/dm-core/adapters.rb:133:in `adapter_ class'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/dm-core-1.2.0/lib/dm-core/adapters.rb:13:in `new'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/dm-core-1.2.0/lib/dm-core.rb:230:in `setup'
        from app.rb:17:in `<main>'