rails 3 doesn't start with ruby script/server ruby: No such file or directory -- script/server (LoadError)

C:\Sites\sample_app>ruby script/server
ruby: No such file or directory -- script/server (LoadError)

C:\Sites\sample_app>rails s
=> Booting WEBrick
=> Rails 3.2.1 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
[2012-06-03 06:13:36] INFO  WEBrick 1.3.1
[2012-06-03 06:13:36] INFO  ruby 1.9.3 (2012-02-16) [i386-mingw32]
[2012-06-03 06:13:36] INFO  WEBrick::HTTPServer#start: pid=1640 port=3000