in full Microsoft Disk Operating System.
personal computers .
MS-DOS was based on DOS, developed in 1980 by Seattle Computer Products. Microsoft Corp . bought the rights to DOS in 1981, and released MS-DOS with IBM's PC that year. Thereafter, most manufacturers of personal computers licensed MS-DOS as their operating system; by the early 1990s more than 100 million copies had been sold. Windows , a {{link=graphical user interface">graphical user interface program based on MS-DOS, became a popular alternative with the release of Verson 3.0 in 1990; Windows 95 fully integrated the operating system and the graphical interface.