Windows 9x

Windows 9x refers to a series of Microsoft Windows operating systems released between 1995 and 2000. It was introduced with Windows 95, a major update to the MS-DOS-based Windows line that extended the 386 Enhanced Mode of previous versions to add support for 32-bit user applications, as well as greatly overhauled the user experience with the introduction of the Windows Explorer. It was succeeded by Windows 98 and then by Windows Me in 2000, after which the series was discontinued and ultimately superseded by Windows XP in 2001.

The series was envisioned as a stopgap to ship a 32-bit consumer version of Windows, as Windows NT at the time was too heavy to run on an average home computer. One of the design constraints of Windows 95 was the ability to run on an average Windows 3.1 machine with a 386 processor and 4 MB of RAM. However, Windows NT required at least three times as much memory and could not be reasonably cut down without major changes to the architectural design. Once home systems became powerful enough to run Windows NT, it was decided to ultimately discontinue the Windows 9x series.

History
Windows 9x began development starting with Windows 95 (codenamed Chicago) in December 1992 as an effort to port the Windows user interface to 32-bit, while keeping the 16-bit MS-DOS as a base. Eventually, Microsoft bundled both MS-DOS and Windows, in a similar fashion to the previous bundles of Windows 3.1 with MS-DOS 5 and 6.

Windows Me received major under-the-hood changes, with the most notable being the removal of the MS-DOS mode.