What is WDDM?
WDDM is an acronym for the Microsoft Windows Display Driver Model. The Microsoft Windows Vista* operating system supports two driver models: WDDM and the XP Display Driver Model (XPDM or XDDM). Drivers based on WDDM provide the 3D graphical Windows Aero* user interface experience. XPDM drivers supply a user interface that visually resembles the Windows* XP/2000 user interface, but they do not support the Windows Aero desktop theme or user interface.