title: rake is not recognized as an internal or external command, my PATH is set correctly
body: <p>I am using ruby 1.8.6 and rake 0.8.7 on Windows now. When I type <code>gem list</code> in the command line, it shows:</p>
  
  <p>rake (0.8.7)</p>
  
  <p>And my path is set correctly to contain the ruby folder. But I still get the error message:
  rake is not recognized as an internal or external command. </p>