Dude, every modern PC comes with a video card that does 3D. It's just a matter of how well it does it. The major factor is how much memory the video card has. In the specs above minimum is 16 megabytes. Reccommended is 64 megabytes. Get the 64 megabytes

Provide a little info, and people could help you better.

What freaking PC do you have? Do you know?

Where'd you buy it? What's the model and model number? Is it a Gateway, Dell or something else?

First off, here's a couple books that everyone should have in their PC library:

How Computers Work

The Hardware Bible

Both will make your PC life a lot easier.

Good Luck