installing ruby on rails 1.9.3 on windows 7

m sorry its a totally newbie question, but m really stuck. please help if possible. after installing everything required to run ruby on rails when i write the command 'rails s' in the command prompt it doesn't start the server. rather it shows :

C:\Sites\railsinstaller_demo>rails s 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 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-1.0.22 /lib/bundler/runtime.rb:68:in `require'         from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.0.22 /lib/bundler/runtime.rb:68:in `block (2 levels) in require'         from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.0.22 /lib/bundler/runtime.rb:66:in `each'         from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.0.22 /lib/bundler/runtime.rb:66:in `block in require'         from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.0.22 /lib/bundler/runtime.rb:55:in `each'         from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.0.22 /lib/bundler/runtime.rb:55:in `require'         from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.0.22 /lib/bundler.rb:122:in `require'         from C:/Sites/railsinstaller_demo/config/application.rb:7:in `<top (requ ired)>'         from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.1 /lib/rails/commands.rb:53:in `require'         from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.1 /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 /lib/rails/commands.rb:50:in `tap'         from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.1 /lib/rails/commands.rb:50:in `<top (required)>'         from script/rails:6:in `require'         from script/rails:6:in `<main>'

Please guide me what to do.. thanks..

You should take a look at this

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 for a list of available runtimes. (ExecJS::RuntimeUnavailable)

Its always useful to look the errors, I’ve seen this problem before you have to add therubyracer gem to you Gemfile (or take a look at the given link)

Javier Q

Install a javascript runtime?

Correct link

did everything. used the rubyracer and copied the source in my gemfile. ran the bundle install again but no use.

maybe i'm doing the process of adding the rubyracer wrong. i would be very thankful if you please guide me through the process. thanks.

Post your Gemfile here.


this is the gemfile without the source of the ruby racer added.

thanks for the help.


Please quote the previous reply so we know what you are talking about without having to go back over previous posts to find the context. Remember this is a mailing list (though you may be posting via a forum).

There is no point posting it without ruby racer as that is the one you need to get working. Also post the output from bundle install Just post it inline, we don't want to mess about downloading files.


therubyracer does not work on Windows due it’s dependency on libv8.

Windows already provides a JavaScript engine, but sometimes it might be missing from your system.

You can simply install Node.JS and restart your computer to ensure “node” executable is available in the command prompt.

Then try your Rails application again.

Luis Lavena wrote in post #1064505:

My hero too!!! =)