Hi:
For the G6-2255eo do the following for W7 x64:
After you install W7, the first driver you need is the AMD chipset driver, which will install the smbus and usb 3 controllers. You only want and need the first file listed on the webpage.
http://support.amd.com/en-us/download/chipset?os=Windows 7 - 64
Then you can use the rest of the W7 x64 drivers and software from this model.
DO NOT USE ANY BIOS OR FIRMWARE DOWNLOADS FROM THIS LINK