Go to the device manager.
There is a Display Adapters category.
Click to expand that category.
Now you will see the name of the display adapter listed there.
If the correct video driver is installed, you should see some model ATI graphics adapter listed there like a Radeon X200.
If the correct video driver is not installed, you will see a Standard VGA Adapter listed there and you will need to install the graphics driver so the video works right.