Win32 Driver Model (WDM) support is implemented in Windows 98 by adding a new layer to the existing VxD device driver architecture that mimics the Windows NT kernel. Ntkern.vxd exposes this interface for WDM drivers, allowing vendors to develop one driver for both Windows 98 and future versions of Windows NT.
For more information about the WDM driver architecture, see "Win32 Driver Model Drivers" earlier in this chapter.
For more information about WDM in general, see Chapter 30, "Hardware Management."