Make sure all the latest drivers for the motherboard are installed. Also, go to AMD's website and try to find a driver there. After the re-install of Windows you have to install all the chipset and other drivers. At the ASUS website, you should be able to find the drivers for the board, including the most current BIOS. In the Device Manager, there should be no alerts for unidentified items, if there are you need to figure them out and get the driver.
To find your motherboard model Download CPU-z, run it and on the "Mainboard" tab it will give you the information you need.
http://www.cpuid.com/softwares/cpu-z.html
That being said, adding a discreet GPU would boost the system performance quite a bit. Upgrading your RAM (if possible) to about 2gb would likely help too.