The Intel(R) Z68 Express chipset requires a special software to be able to support switchable graphics configurations, in which you can benefit from the features on the Intel® HD Graphics 2000 while using the monitors connected to a video card.
In this case, the configuration is supported while using the monitors to one single video adapters and a software bypasses the processing between the two video controllers. having one monitor physically connected to each video adapter is not the way how this is designed and certified to work.
In the other hand, drivers for this video controller are only provided by the operating system itself and it would be updated through Microsoft* updates. In this case, if you would like to test a driver update then check with Microsoft* or through Windows* updates at: