Driver Design

A device driver functions as an extension of the Windows operating system. Therefore, driver developers must design the driver carefully to build in reliability, serviceability, and the feature-based functionality needed to support the driver’s device. Device drivers for Windows are implemented as user-mode or kernel-mode drivers.

User-mode drivers: These drivers typically provide an interface between a Win32 application and kernel-mode drivers or other operating system components. In Windows Vista, all printer drivers execute in user mode. By using the user-mode driver framework (UMDF), you can create user-mode drivers that support devices that are based on a protocol or serial bus.

Kernel-mode drivers: These drivers execute as part of the kernel-mode operating system components that manage I/O, Plug and Play, memory, processes and threads, security, and so on. Kernel-mode drivers are typically layered. All kernel-mode drivers supply a set of system-defined standard driver routines.

Some kernel-mode drivers are Windows Driver Model (WDM) drivers that comply with the WDM. Some drivers are kernel-mode driver framework (KMDF) drivers. Other drivers might be based on NDIS or other driver models that are specific to a device class.

For best practices for instrumenting your driver, see About Tools for Verifying and Testing Drivers.