What is a 386 file and how do I open a 386 file?

386 is a device driver file used by Windows 3.x systems. It allows one or more hardware devices to communicate with the computer, and 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.