Final answer:
No, Microsoft did not invent DOS but they played a significant role in its popularization and commercialization through their version called MS-DOS.
Step-by-step explanation:
No Microsoft did not invent the Disk Operating System (DOS). DOS was originally developed by researchers at AT&T Bell Labs and the University of California, Berkeley. However Microsoft played a significant role in the popularization and commercialization of DOS through its version called MS-DOS which was widely used on personal computers in the 1980s and 1990s.