I have been going through Sitepoints Simply Rails 2 book. I am at the part where I create a text file (I used Context) and save it as an .rb file. I did what the book says and saved it and tried to run the $ ruby filename.rb at the command prompt and I get the following error," 'ruby' is not recognized as an internal or external command, operable program or command." I am not sure what I am missing and the book doesn't really specify. I have tried to change the directory also and run it with no luck. Am I suppose to run this from the command line or the "Ruby" console window? If anyone can tell me what I am doing wrong/missing I would be greatly appreciative.