ruby-on-rails - レール上のルビーの宝石

Question

Windows OS のコマンド プロンプトで Rails サーバーを実行しようとすると、次のエラーが表示されます。

C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/execjs-1.4.0/lib/execjs/run
times.rb:51:in `autodetect': Could not find a JavaScript runtime. See https://gi
thub.com/sstephenson/execjs for a list of available runtimes. (ExecJS::RuntimeUn
available)
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/execjs-1.4.0/l
ib/execjs.rb:5:in `<module:ExecJS>'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/execjs-1.4.0/l
ib/execjs.rb:4:in `<top (required)>'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/coffee-script-
2.2.0/lib/coffee_script.rb:1:in `require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/coffee-script-
2.2.0/lib/coffee_script.rb:1:in `<top (required)>'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/coffee-script-
2.2.0/lib/coffee-script.rb:1:in `require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/coffee-script-
2.2.0/lib/coffee-script.rb:1:in `<top (required)>'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/coffee-rails-3
.2.2/lib/coffee-rails.rb:1:in `require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/coffee-rails-3
.2.2/lib/coffee-rails.rb:1:in `<top (required)>'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.3.4/
lib/bundler/runtime.rb:72:in `require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.3.4/
lib/bundler/runtime.rb:72:in `block (2 levels) in require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.3.4/
lib/bundler/runtime.rb:70:in `each'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.3.4/
lib/bundler/runtime.rb:70:in `block in require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.3.4/
lib/bundler/runtime.rb:59:in `each'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.3.4/
lib/bundler/runtime.rb:59:in `require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.3.4/
lib/bundler.rb:132:in `require'
        from C:/Sites/priya/config/application.rb:7:in `<top (required)>'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.1
3/lib/rails/commands.rb:53:in `require'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.1
3/lib/rails/commands.rb:53:in `block in <top (required)>'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.1
3/lib/rails/commands.rb:50:in `tap'
        from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.1
3/lib/rails/commands.rb:50:in `<top (required)>'
        from script/rails:6:in `require'
        from script/rails:6:in `<main>'

execjs をダウンロードし、ファイルをプロジェクト フォルダーにコピーしました。しかし、変化はありません。この問題を解決する方法を教えてください。