discontinued operating system for x86

MS-DOS is a computer operating system by Microsoft Corporation. It stands for "Microsoft Disk Operating System", and came from an operating system Microsoft bought called 86-DOS, originally called QDOS, or "Quick and Dirty Operating System." The operating system used a command-line interface for the user to input commands. It was popularly used in PCs before a GUI operating system called Microsoft Windows came out, and still is used in some places today.

An example of the MS-DOS command-line interface, showing that the current directory is the root of drive C
Written inx86 assembly,[1] later versions also used C
OS familyDOS
Working statePreserved pieces exist in 32-bit Windows
Source modelClosed source; open source for select versions since 2018[2]
Initial releaseAugust 12, 1981; 40 years ago (1981-08-12)[3]
Final release8.0 / September 16, 2000; 21 years ago (2000-09-16)
Update methodRe-installation
Package managerNone
Kernel typeMonolithic
user interface
Command-line, text
MIT License (v1.25 & v2.0)[2]
Succeeded byWindows NT (as of Windows XP)
Official websiteMS-DOS overview
Support status
MS-DOS 6.0 unsupported as of December 31, 2001[4]
Starting MS-DOS

OS/2 was made to replace MS-DOS, but that replacement did not succeed. MS-DOS was the framework behind Windows operating systems until an operating system known as Windows XP.

MS-DOS is a text-based operating system, meaning that a user works with a keyboard to input data and receives output in plain text. Later, MS-DOS often had programs using a mouse and graphics to make work more simple and quick. (Some people still believe that working without graphics is really more efficient.) It is called a disk operating system because it was originally made to be loaded into a computer's memory with a floppy disk each time the computer is started (booted) up.

MS-DOS was released as proprietary software, but decades later after most users had gone to other systems, it was released as free software.[2]

How-To BooksEdit

Many books were written on how to use MS-DOS. A popular introductory book was MS-DOS for Dummies, by Dan Gookin, the book in the For Dummies series of easy to follow instruction books.


  1. Paterson, Tim (June 1983). "An Inside Look at MS-DOS". Seattle Computer Products. Seattle. Archived from the original on May 6, 2017. Retrieved June 10, 2019.
  2. 2.0 2.1 2.2 Turner, Rich. "Re-Open-Sourcing MS-DOS 1.25 and 2.0". Windows Command Line Tools For Developers. Retrieved 29 September 2018.
  3. "MS-DOS: A Brief Introduction". The Linux Information Project. Archived from the original on December 14, 2017. Retrieved December 14, 2017.
  4. "Obsolete Products Life-Cycle Policy". Support. Microsoft. July 30, 2009. Archived from the original on July 6, 2006. Retrieved April 6, 2010.