MS-DOS:

The commonly used operating system which is commercialized by Microsoft is MS-DOS. It was the most commonly used member of the DOS family of operating systems and was the dominant operating system for computers during the 1980s. It was based on the Intel 8086 family of microprocessors, particularly the IBM PC and compatibles. It was gradually replaced on consumer desktop computers by operating systems offering a graphical user interface, in particular by various generations of the Microsoft Windows operating system. It was originally known as QDOS and 86-DOS.