Additional help:
Click
here if you have an Nvidia graphics card and download the appropriate driver based on OS and series.
Click
here if you have an ATI graphics card and download the appropriate driver based on OS and series.
If you don't know what your card is, hit WinKey + "R", type "dxdiag" (no quotes), and hit "Enter". The "Display" tab will tell you the manufacturer. You should be up to date with DirectX, but if it turns out that this is not the case, visit
this page to download the update app.