CONFIG.SYS is a text file containing disk operating system (DOS) commands that tell the operating system (OS) how the computer is initially set up. More specifically, CONFIG.SYS commands specify ...

Before Windows was created, the most common operating system that ran on IBM PC compatibles was DOS. DOS stands for Disk Operating System and was what you would use if you had started your computer ...

While Windows has moved away from using Microsoft Disk Operating System as a base, versions of DOS still persist. Some programs refuse to run in modern versions of Windows and require a DOS emulator.