ousyous, welcome to the Seven Forums.
The reason you can't find a Windows 7
driver for it is the same as the desktop version of it, there isn't one because ATI never made one and hasn't made a driver for that range of laptop and desktop cards since about 2006. The best you're going to get for it is to use the last XP driver for it from the laptop manufacturer as the desktop version of that driver will not install on it.