(VxD) A device driver under {windows 3.x}/{windows 95} running as part of the {kernel} and thus having access to the memory of the kernel and all running processes as well as raw access to the hardware. VxD' s usually have the filename extension .386 under windows 3.x and .vxd under windows 95. VxD' s written for windows 3.x can be used under windows 95 but not vice versa. (1997-02-27)