VxD
VxD is the device driver model used in Microsoft Windows/386, the 386 enhanced mode of Windows 3.x, Windows 9x, and to some extent also by the Novell DOS 7, OpenDOS 7.01, and DR-DOS 7.02 (and higher) multitasker. VxDs have access to the memory of the kernel and all running processes, as well as raw access to the hardware.
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