ONLY FOLLOW THIS POST IF YOU FEEL COMFORTABLE RUNNING UNSIGNED DRIVERS AND REALIZE THAT YOU WILL HAVE BLUE SCREENS IF YOU DO NOT DO THIS PROPERLY, AND THIS MAY TEMPORARILY DISABLE ALL YOUR USB DEVICES IF NOT DONE PROPERLY!
I use my PS3 controller on 64 bit vista and this is how:
If you follow the instructions EXACTLY, you will be good to go. You also need to install ReadyDriverPlus found here:
This will automatically disable driver signature enforcement on startup. If you don't do this, your machine WILL blue screen due to having an unsigned driver(the only thing I don't like about Vista...).
WORD OF CAUTION!
You MUST disable driver signature enforcement on EVERY boot for this to work properly. It you do not, you will either blue screen crash or temporarily disable most or all of your USB devices. If this happens, you merely have to disable them in hardware manager and re-enable them.
ONLY USE THIS HALF-ASS WORKAROUND IF YOU FEEL COMFORTABLE RUNNING UNSIGNED DRIVERS!
I have used this method myself and my Dualshock 3 controller works perfectly with my PC, so it DOES work, but since the libusb64 drivers are fairly recent, there is a high potential something won't work right on your PC.
It's unfortunate that this is the only method to get a PS3 controller working on your PC with an x64 operating system because it's such a pain, but the libusb32 drivers simply do not do anything for x64 operating systems.