At least some NVIDIA"s ForceWare drivers cannot pass certain WHQL tests as Microsoft"s Display Compatibility Test does not pass pixel shaders 3.0 along with some other pixel shaders tests on the drivers version 66.81. Earlier this year Microsoft"s test rejected another important technology – Geometry Instancing, but on ATI"s CATALYST drivers.
The Microsoft Display Compatibility Test kit is intended for testing display adapters and chipsets along with their drivers in order to verify their compliance with Windows XP and Windows Server 2003 operating systems and Microsoft DirectX 7, DirectX 8.1a and DirectX 9.0c specifications, which means that the test determines whether one or another hardware/software feature functions properly. Typically DCT is required to pass WHQL validation, which is important for OEMs and large system builders as well as end-users.