If Device Manager shows "Standard VGA Graphics Adapter" even after installing drivers, you have a conflict. Right-click the device in Device Manager, select "Update Driver Software," and browse your computer for the driver files manually (extract the .exe file using 7-Zip or WinRAR if necessary to find the .inf files).
If you are reinstalling Windows 7 or replacing a hard drive, you'll need specific drivers to make the hardware work correctly. Sony Vaio Vpceh25en Drivers For Windows 7 64 Bit