Problem in window service

Actually i am new for ruby, i done mail sending application in
ruby and now i am trying to implement that mail application as a window
service. But it always showing one error , i don’t know how to solve
this error

‘gem_original_require’: no such file to load – win32/daemon (LoadError)
from c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
from BulkMail.rb:8

If anyone know about this error means, pls help me.

Thanks in advance