I had that problem with several games. As I changed video cards I got more and more trouble with games, specially older ones. I just tried several combinations in my NVIDIA control panel (GeForce 9400GT) and I finally got a normal speed in one of the games with trouble. In my case, in each configuration (3D configuration controler) has a description and usual situations (they appear when you leave your mouse pointer over the characteristic). There I found that some recommended certain settings for older games. I changed those and also turned some quality options to a higher graphic configuration. It worked! I will now install other games that I have uninstalled for that problem, and I hope they'll work to.
