WDDM 1.2 driver enforcement

Validation by the Microsoft DirectX graphics kernel subsystem (Dxgkrnl) is enforced starting with Windows 8 to determine whether the mandatory Windows Display Driver Model (WDDM) 1.2 features are supported by the WDDM 1.2 driver.

WDDM 1.2 has both mandatory and optional features. The driver must set all the mandatory feature caps to claim itself as a WDDM 1.2 driver, while the driver can implement any combination (or none) of the optional features. A non-WDDM 1.2 driver must report none of the WDDM 1.2 features.

User experience when a driver fails the Dxgkrnl validation

If a driver has wrongly claimed itself as WDDM 1.2 or has implemented only some of the mandatory features, then it will fail to create an adapter, and the system will fall back to the Microsoft Basic Display Driver (MSBDD).