Solution
We strongly recommend you to use ASUS official VGA driver built in driver DVD. For this issue, please follow below steps to solve it.
1. Uninstall the ATI VGA driver

2. Reboot the computer
3. Reinstall the VGA driver from ASUS driver DVD or ASUS support site.
http://support.asus.com/download/download.aspx?model=G73JH&f_name=VGA_WIN7_64_868300.zip&f_type=1&os=30

4. Restart the computer