Device driver file used by Windows 3.x systems; allows one or more hardware devices to communicate with the computer; may also add support for internal components; "386" comes from the type of processor used in many early Windows machines. The WINA20.386 file is a read-only file that is copied to the root directory of the startup drive during an MS-DOS 5 or 6 upgrade. It is used for running in "386 enhanced mode." NOTE: Beginning with Windows 95, device drivers have a .VXD file extension.