Hello and welcome to the forums
Do a clean reinstall if your VGA driver,here is how:
1_Download and install "Driver Sweeper" from here:http://www.guru3d.com/category/driversweeper/
2_Remove the current driver from add/remove programs and restart and boot to safe mode.
In safe mode and open Driver Sweeper,choose ATI and click remove.
3_Restart and boot normally to windows and install the driver again,after the installation restart the PC and see if it works then or not