How do I configure a controller bean?

Why can't I configure the buttons on my Playstation controller so it works with Sonic Generations on the PC?

• I just found out that you can use a Playstation controller to play Sonic Generations downloaded through Steam. In Steam if you can go into your games library right click Sonic Generation you can choose configure and from their choose to you a Playstation controller. But, when you go into that it gives you a picture of an Xbox controller, you click the buttons on it and press the button on the Playstation controller that you want to do the same thing. But that won't work. Please help, thanks.

• Answer:

  then don't use steam, the game comes on like 3 DVD's. install the game, then start the game, then the game has options for you to map your controller. or you could just get the game from a torrent if you really wanted to.