That warning probably is the digital signing warning that appears that says that this device has not been digitally signed by Microsoft Corp. and may cause problems and instability in your system. And it gives 2 options, Continue Anyways or Stop the Installation (or something to that effect)
All it means is that Microsoft has not certified that version of drivers as of yet as being 100% without-a-doubt compatible... But if you downloaded the right version for your video card, you will be fine by selecting Continue Anyways (guessing that you are running XP probably)
Shut yo face before I punch you in the mouth, break your teeth and call you Snaggle-tooth.