MS-DOS, the leading disk operating system from Microsoft, was first published in 1981. MS-DOS is the first commercially available operating system. It was inspired by the CP/M operating system that was common at the time and was expanded to include additional functions. In the early 1980s, IBM commissioned Microsoft to develop a 16-bit operating system. IBM planned to acquire the full text-based operating system DOS and use it in its future personal computer models. However, Bill Gates, the founder and owner of Microsoft, did not want to give up control. In 1982, more than 50 companies entered into a license agreement to use Microsoft’s Disk Operating System for their own purposes. This is the time when DOS and Microsoft became extremely relevant. In the following years there was a desire for a graphical user interface and that is when Windows was born. With the release of Windows, Microsoft put the focus on GUI based operating systems and DOS moved into the background. Windows 95 was the gradual end of MSDOS, in years to come DOS became less and less important with each new version of Windows.