Windows 2.0 and some applications. Windows 2.0 set up Windows 3.0 by allowing a protected mode kernel that allowed multitasking of MS-DOS applications, but Windows applications all shared a ...

Except it didn’t. MS-DOS took over the word and led — eventually — to the huge number of Windows computers we know today. Microsoft has released the source code to MS-DOS 1.25 and 2.0 on GitHub.