do you have $400 or so? You can get a 2 generation old card for around that. I know that can be a lot (you can buy a basic school/work laptop for that much!), but its nothing like the current series prices.

The way PCs are set up, there is a rudimentary graphics card on many motherboards that can let you run windows and some simple 2-d stuff -- this sounds like what you current have. It is not sufficient for most real games (3-d or advanced 2d that has lighting and such).