When the Playstation 3 first came out, people wondered if it would work on their PC via a USB connection. As it turned out, Vista detected the controller, but button inputs did not work. Some solutions came out, such as the use of libusb, but that never worked with Vista and in fact disabled USB completely.
Now there is a solution to use the PS3 controllers (SixAxis and DualShock 3) in Windows Vista. All it takes is a simple driver found here.