Newbie can't figure out how to install restful_authentication plugin

I get this message when I try to install restful_authentication plugin
and I am stuck. I am running Windows Vista (don’t ask…).

ruby script\plugin install -r 3072
git://github.com/technoweenie/restful-authentication.git
c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
gem_original_re quire': no such file to load -- ./script/../config/../vendor/rails/ railties/lib/ initializer (LoadError) from c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb: 27:inre
quire’
from ./script/…/config/boot.rb:46:in load_initializer' from ./script/../config/boot.rb:39:inrun’
from ./script/…/config/boot.rb:11:in boot!' from ./script/../config/boot.rb:109 from c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb: 27:inge
m_original_require’
from c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:
27:in `re
quire’
from script/plugin:2

Ignore the -r 3072, that was from the svn location i tried. Output is
the same.