Windows Friendly Editors
RubyInstaller doesn’t come with an editor bundled, but nothing is stopping you from installing it manually. The following are links to different pages that describe either installation steps to get them working, or a list with recommended editors.
You should try it, at least.
Marcos Ricardo has published installation steps for Ruby 1.9.1 and configuration of SciTE, which you can take a look here
Netbeans it’s a great IDE to develop applications on ruby, ruby support it’s great, it comes with a gems installation manager, supports RubyInstaller and all those IDE features like code completation, debugging, code bookmarks, code formatting, etc, check this to setup ruby on Netbeans
Here is a list of editors look for windows compatible, and have fun!
More are listed here