No such file to load -- gem_prelude.rb (LoadError)

Hi,
I am new to IronRuby. I have installed IronRuby1.1. When I execute my
IronRuby script I get an error:

unknown: no such file to load – gem_prelude.rb (LoadError)

Can someone tell me why this error is occuring???
I am trying to automate using Bewildr.
This is my script:

require ‘rubygems’
require ‘bewildr’
puts “hello”
@app = Bewildr::Application.start(‘C:/Documents and
Settings/Desktop/ExpenseItStandalone.exe’)

Thanks in advance,
Sophia