The MicrosoftÒ WindowsÔ Device Driver Kit (DDK) provides documentation, tools, and sample sources that you need to develop Microsoft Windows device drivers and virtual devices.
Windows device drivers provide the device-specific Windows support to provide Windows-based applications access to displays, printers, keyboards, pointing devices, and other input and output devices.
Windows virtual devices provide the device management Windows needs when operating in 386 enhanced mode. Virtual devices ensure that the computer's actual devices continue to operate correctly, even though two or more applications access the devices at the same time.
The DDK provides what you need to build, test, and debug new Windows device drivers and virtual devices. It also provides what you need to modify (if necessary) existing drivers and virtual devices to ensure that they work properly under the current version of Windows.