I have installed a driver that works for win7 32bit (build 7100). I've made a Video, I'll upload it for you because it's not so easy as i thout first...

Windows 7 installs two drivers and not only one. And it is not so easy to update the drivers with your own because Windows thinks his drivers are better then the one you choose...
For those who can't wait for the Video:
Download the driver here:
File Details-PS3-DualShock-3-Controller-Drivers-PlayStation-3 -
Let install Win7 the drivers for the controller (the controller will not work...)
Search the two drivers with the method from Drago1 and update the one that is NOT called something like "gamecontroller".
Click on "Search the Driver on Your Computer"
Click on "Select from a List of Drivers on the Computer"
Click on "Volume" (or something like that) and search the downloaded driver.
Everything should work fine (maybe you have to click the PS-Button first).
Maybe the name's are not really correct because my systemlanguage is German and not English... Sorry

Here a List which JoyKey is which Button on the Controller:
1-Select
2-L3
3-R3
4-Start
5-Up (DigiPad)
6-Right
7-Down
8-Left
9-L2
10-R2
11-L1
12-R1
13-Triangle
14-Circle
15-Cross
16-Square
17-PS-Button
18&19-nothing
Hope everything is clear and you can use all your PS3-Controller with Windows7

MfG Bluemond
EDIT: Here the Video:
Video Tutorial