Getting Started with 'Windows Drivers'

When you write a driver to run on the Windows operating system, you have two basic choices. You can write a Windows Desktop driver, which only runs on Windows Desktop editions. Or, you can meet a few extra requirements and write a Windows Driver, which runs on both Desktop and non-Desktop variants of Windows. The Windows Driver classification extends and replaces the older Universal Driver classification.

The following additional requirements apply to Windows Drivers:

• Compliant with DCH Design Principles.
• Follow the principles of Driver Package Isolation.
• Follow API Layering Requirements.
• Certified with Windows Hardware Compatibility Program Certification Process using the Hardware Lab Kit. WHCP Certification Process requirements apply to both KMDF and UMDF drivers.

The following table summarizes the distinctions between the two classifications:

Feature	Windows Drivers	Windows Desktop Drivers
Runs on Windows Desktop	Yes	Yes
Runs on non-Desktop variants of Windows	Yes	No
Must be certified with WHCP	Yes	No
WDK & HLK are primary vehicles for developing and certifying drivers	Yes	Yes
Adhere to stricter reliability and serviceability requirements (e.g. driver package isolation)	Yes	No

While it's not required for a driver running only on Windows Desktop to meet the additional requirements for a Windows Driver, doing so enhances driver serviceability and reliability, and also prepares the driver for possible future certification on non-Desktop variants of Windows.