i am trying paperclip for the first time and followed this tutorial

all is well until i use styles. this is the code

has_attached_file :photo, :url => "/uploads/products/:id/:style/:basename.:extension",  
:path => ":rails_root/public/uploads/products/:id/:style/:basename.:extension",
:styles => { :thumb=> "100x100#" }

the error i see on the console is

[paperclip] An error was received while processing: #<Paperclip::NotIdentifiedByImageMagickError: C:/DOCUME~1/LOCALS~1/Temp/stream,2956,1.jpg is not recognized by the 'identify' command.>

what does this mean? I have no idea what it means. Should i install this ImageMagick?

I tried installing it as a plugin as per this page. This also returns an error that "plugin not found".

what am i missing here?