The development of Windows 95 (codenamed Chicago) began around March 1992, just after the release of

Windows 3.1 Windows 3.1 is a major release of Microsoft Windows. It was released to manufacturing on April 6, 1992, as a successor to Windows 3.0. Like its predecessors, the Windows 3.1 series run as a shell on top of MS-DOS; it was the last Windows 1 ...

and designed to be the successor to both Windows 3.1 and Microsoft's text-based

MS-DOS MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few op ...

. At this time, Windows for Workgroups 3.11 and

Windows NT 3.1 Windows NT 3.1 is the first major release of the Windows NT operating system developed by Microsoft, released on July 27, 1993. It marked the company's entry into the corporate computing environment, designed to support large networks and to be ...

were still in development at

Microsoft Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The ear ...

Windows 95 Windows 95 is a consumer-oriented operating system developed by Microsoft and the first of its Windows 9x family of operating systems, released to manufacturing on July 14, 1995, and generally to retail on August 24, 1995. Windows 95 merged ...

was eventually

released to manufacturing The software release life cycle is the process of developing, testing, and distributing a software product (e.g., an operating system). It typically consists of several stages, such as pre-alpha, alpha, beta, and release candidate, before the fi ...

on July 14, 1995, and generally to retail on August 24, 1995.

Background

During the initial design and planning of

in 1992,

's strategy was to have a next generation, high-end OS based on Windows NT, namely,

Cairo Cairo ( ; , ) is the Capital city, capital and largest city of Egypt and the Cairo Governorate, being home to more than 10 million people. It is also part of the List of urban agglomerations in Africa, largest urban agglomeration in Africa, L ...

, and a low-end, consumer-focused one as an evolution of Windows 3.1. The latter strategy was to develop a 32-bit underlying kernel and filesystem with 32-bit protected mode device drivers in Windows for Workgroups 3.11, to be used as the basis for the next version of Windows, code named "Chicago". Cairo would be Microsoft's next-generation operating system based on Windows NT featuring a new user interface and an object-based file system, but it was not planned to be shipped before 1994 (Cairo would never be shipped, however, although elements from the Cairo project would eventually ship in late July 1996 in Windows NT 4.0, without the object-based file system, which would later evolve into

WinFS WinFS (short for Windows Future Storage) was the code name for a canceled data storage and management system project based on relational databases, developed by Microsoft and first demonstrated in 2003. It was intended as an advanced storage subsy ...

). Simultaneously with Windows 3.1's release,

IBM International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...

started shipping OS/2 2.0. Microsoft realized they were in need of an updated version of Windows that could support 32-bit applications and preemptive multitasking, but could still run on low-end hardware (Windows NT, requiring 12 MB RAM and 75 MB disk space, did not). Initially, the "Chicago" team did not know how the product would be packaged. Initial thoughts were there might be two products, MS-DOS 7, which would just be the underlying OS, an evolution of the Windows for Workgroups 3.11 kernel, with a character mode OS on top, and a fully integrated graphical Windows OS. But soon into the project, the idea of MS-DOS 7 was abandoned and the decision was made to develop only an integrated graphical OS Windows "Chicago".

History

The Chicago project was led by Brad Silverberg, who, at that time, was senior vice president of the personal systems division at Microsoft. Microsoft's product plan looked as follows: Prior to the official release, the American public was given a chance to preview Windows 95 in the Windows 95 Preview Program. For US$19.95, users were sent a set of 3.5-inch floppy diskettes that would install Windows 95 either as an upgrade to Windows 3.1x or as a fresh install on a clean computer. Users who bought into the program were also given a free preview of The Microsoft Network (MSN), the online service that Microsoft launched with Windows 95. During the preview period Microsoft established various electronic distribution points for promotional and technical documentation on Chicago including a detailed document for media reviewers describing the new system highlights. The preview versions expired in November 1995, after which the user would have to purchase their own copy of the final version of Windows 95.

Notable beta milestones

Several Windows 95 betas were released before the final launch:

References

{{Microsoft Windows family Windows 95