Hi Gibbo, and
You'll have to give us some more information before someone can help you.
1. Which Operating System are you using? (XP, ME, Win9X?)
2. Do you know which graphics card you have?
3. Have you got the latest drivers for it?
4. What are the symptoms of the problem? Do you get any error messages? Is it only a problem with some games and not others?
5. Have you got the latest version of DirextX, compatible with your graphics card? I think the latest version is 9, but not all graphics cards are compatible.
If you can give us some of the above info, I'm sure one of our techies will be able to help you.