Try this driver, to make the driver work, you need to open up the device manager in Windows. Go the the "My Computer" icon and right-click it. When the context menu appears, click properties. From there, you should be able to open the Device manager from the left side of the window. If your having trouble finding it, then go to start and search "device manager". Click on the correct result when it appears. Once you have the device manager open, expand the "display adapters". Right click on the device and when the context menu appears, press update driver. A window will open to help you through the whole process. It will be easier if you choose to browse to the location that you save this file to. Remember to click on the .ini file because it holds the information needed to intsall this driver. Click next, select your driver again, and your done. If you can't do this automatically, use the option to pick from a list of device drivers on my computer and broswe to the extracted files.
I tried it on a Acer Veriton 3600gt with the same chipset... i checked the bios settings to your described... It does work at the welcome screen, but as soon as 7 loads the main workspace it hangs and blue screens... did ou get any further with this???