Basic problem in running ModelToRad.rb

Hi,

Basic question as a beginner in Radiance: I want to run ModelToRad.rb
using Windows CMD command line:

ruby ModelToRad.rb test_01.osm

But I get the following error:

C:/Ruby193/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require':
cannot load such file -- openstudio (LoadError)
        from C:/Ruby193/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in
`require'
        from ModelToRad.rb:45:in `<main>'

Should I put the path to Openstudio.exe in the require command? What
about the other "require" lines:

require 'openstudio'
require 'openstudio/energyplus/find_energyplus'
require 'fileutils'

require 'optparse'
require 'ostruct'

Best,

···

--
M.Sc. Farhang Tahmasebi
Department of Building Physics and Building Ecology
Vienna University of Technology