How do I get the Xbox 360 controller to play games on my computer?

I've got an Xbox 360 controller for use with my computer and installed the software that came with it on a disc.



However, when I play games like Team Fortress 2 and Grand Theft Auto: SA, they do not work very well (only a few actions mapped) or not at all. How can I change this and get the games to work with the controller?How do I get the Xbox 360 controller to play games on my computer?
I would recommend using the keyboard and mouse controls, they are much better for first person shooters.How do I get the Xbox 360 controller to play games on my computer?
You have to go into the game's options menu and re-map the controller's button with the actions you want.