RefineryCMS app creation problem in Windows XP

I'm having real problems getting refinerycms to work on Windows. I have got the installation working correctly on a Windows 7 machine at work and have copied the set-up for home, but I just get this error every time I try and create a new app.

$ refinerycms testapp --heroku
c:/Ruby/lib/ruby/gems/1.9.1/gems/refinerycms-1.0.8/bin/refinerycms:444:in ``': N
o such file or directory - cmd /c " "c:\Ruby\bin\ruby" -S  rails --version " (Er
rno::ENOENT)
    from c:/Ruby/lib/ruby/gems/1.9.1/gems/refinerycms-1.0.8/bin/refinerycms:
444:in `run_command'
    from c:/Ruby/lib/ruby/gems/1.9.1/gems/refinerycms-1.0.8/bin/refinerycms:
173:in `validate!'
    from c:/Ruby/lib/ruby开发者_运维知识库/gems/1.9.1/gems/refinerycms-1.0.8/bin/refinerycms:
135:in `run!'
    from c:/Ruby/lib/ruby/gems/1.9.1/gems/refinerycms-1.0.8/bin/refinerycms:
468:in `<top (required)>'
    from c:/Ruby/bin/refinerycms:19:in `load'
    from c:/Ruby/bin/refinerycms:19:in `<main>'

I'm really lost now as what to do. Just wish I had a mac to work on!

Any help much appreciated.