Question: What is directX and what does it do? Do you have to install an actual part into the computer or just download info? Does it have anything to do with your sound card and/or graphics?
Answer: DirectX is software. It is a special utility that you install onto windows to provide enhanced multimedia capability - particularly with respect to 3D graphics. Most games require a particular version of directX (or later) to be installed in order for the game to work.
If you don't already have a copy of directX you can download it directly from Microsoft.
This article written by Stephen Chapman, Felgall Pty Ltd.