Installing radiant gem with Ironruby

Hi everyone,

Does anyone have experience installing radiant with IronRuby?
I receive this error

PS U:> igem install radiant --no-ri --no-rdoc
Building native extensions. This could take a while…
ERROR: Error installing radiant:
ERROR: Failed to build gem native extension.

“C:/Program Files/IronRuby 1.0v4/bin/ir.exe” extconf.rb
can’t find header files for ruby.

Gem files will remain installed in C:/Program Files/IronRuby
1.0v4/lib/ironruby/gems/1.8/gems/RedCloth-4.2.3 for inspect
Results logged to C:/Program Files/IronRuby

Thank you in advance

Eduardo B.