The Standard VGA graphics adapter driver is the default driver Windows uses when it can't find the correct specific driver for the graphics card. It has very limited capabilities - such as low maximum resolution.
I suggest you install the latest Windows 7 driver specific to your graphics card. Get it from your PC manufacturer in the first instance or, failing that, the manufacturer of the graphics card. Common manufacturers of graphics cards/adapters are nVidia, Intel and AMD/ATi.