well, theres 2 ways (that i know of). One is MotioninJoy http://www.howtogeek.com/howto/45610/how-to-use-your-ps-3-controllers-as-a-joystick-for-your-windows-pc/
and the other is a simple SIXAXIS driver http://dl.qj.net/playstation-3/tools-and-utilities/sixaxis-driver-for-pc.html
I use the second one. Apparently, it might be a little weird getting it working on windows 7. I use it on windows 7 though. What i do is, connect the pad to the usb port, run the ps3sixaxis_en.exe, press the Home button, run the exe again, and it should work.
If you're planning on releasing a game, allowing gamepad support, i would advise sticking to actual pc gamepads though, like a logitech pad or the 360 pad even though theres that axis bug/issue, which does actually affect the game, because, if your character can move, it will be moving.
I was thinking of how to get around it, and thought maybe needing to "press start" to load the main game menu (like for example, in street fighter game and so on). That might be enough to set the axis back to 0, right?