If it's a really new game, with a newer video card, updating your drivers might fix things.
If it's a really new game, with a really old video card, you need to update/replace your card.
Many current games are written to take advantage of the newer capabilities in modern video cards. But in the process, really old video cards capabilities can/will be dropped. A good example is anything by 3dfx, most recent games won't support the cards.
On the other hand, if it's an older game, the difference in the age of the game and your video card could be the problem.
Many older games will often work just fine on newer systems, or newer video cards. But they'll still b#tch about it because the video card doesn't match any it has in it's data base. So the game thinks your trying to run on an older or unsupported video card.
I have a hunch, because I've run into it myself a few times, that this last one is your problem. The really sh#tty thing is that sometimes the game will refuse to run any way, simply because it doesn't see any of the cards it was designed for.
A prime example of this is, I can run NFS3, NFS Porsche, NFS High Stakes 2, but I can't run NFS High Stakes in anything other then software mode. All the other games will run on my Geforce 4Ti 4400, but HS balks at my video card, big time.