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 portable, compiled for Intel x86, DEC Alpha and MIPS based workstations and servers. It was Microsoft's first 32-bit operating system, providing advantages over the constrictive 16-bit architecture of previous versions of Windows that relied on DOS, but retaining a desktop environment familiar to Windows 3.1 users.
Windows NT began as a rewrite of the OS/2 operating system, which Microsoft had co-developed with IBM but failed to gain much traction against Unix, with vendor Sun Microsystems dominating the market for powerful desktop workstations. For several reasons, including the market success of Windows 3.0 in 1990, Microsoft decided to advance Windows rather than OS/2 and relinquished their OS/2 development responsibilities. By extending the Windows brand and beginning NT at version 3.1, like Windows 3.1 which had established brand recognition and market share, Microsoft implied that consumers should expect a familiar user experience. The name Windows NT ("New Technology") advertised that this was a re-engineered version of Windows.
First publicly demonstrated at Comdex 1991, NT 3.1 was released in 1993 in two editions: Workstation and Advanced Server. When Windows NT premiered, their sales were limited by high system requirements, and a general lack of 32-bit applications to take advantage of the OS's data processing capabilities. It sold about 300,000 copies before it was succeeded by Windows NT 3.5 in 1994. On December 31, 2000, Microsoft declared Windows NT 3.1 obsolete and stopped providing support and updates for the system.
Development history The origins of Windows NT date back to 1988, where Microsoft had a major foothold on the personal computer market due to the use of its MS-DOS as the operating system of IBM PC compatibles. Nathan Myhrvold, who had joined Microsoft after its acquisition of Dynamical Systems Research, identified two major threats to Microsoft's monopoly—RISC architectures, which proved to be more powerful than the equivalent Intel processors that MS-DOS ran on, and Unix, a family of cross-platform multitasking operating systems with support for multiprocessing and networking. While the widespread use of Unix was hindered by the need to adapt programs for each individual variant, Bill Gates believed that the combination of a Unix-like operating system with RISC processors could be a market threat, prompting the need for Microsoft to develop a "Unix killer" that could run on multiple architectures. Myhrvold wanted to develop a new system that would run on RISC workstations and Intel chips and multiprocessing computers. Gates had also hired Dave Cutler from Digital Equipment Corporation to assist in developing the new operating system; Cutler left DEC after the cancellation of the PRISM architecture and its MICA operating system, and agreed to join Microsoft on the condition that he be able to bring a number of staff members from his team at DEC with him. Cutler arrived at Microsoft in October 1988, and began working on the development of the operating system in November.
The operating system was first developed as a revised version of OS/2, an operating system Microsoft had jointly developed with IBM. While OS/2 was originally intended to succeed MS-DOS, it had yet to be commercially successful. The OS was to be designed so it could be ported to different processor platforms, and support multiprocessor systems, which few operating systems did at that time. To target the enterprise market, the OS was also to support networking, the POSIX standard, and a security platform compliant with the "Orange Book" standards; which would require the OS to be a multi-user system with a permission framework and the ability to audit security-related events.
Both Microsoft and IBM wanted to market an operating system that appealed to corporate "enterprise software" customers. That meant greater security, reliability, processing power, and computer networking features. However, since Microsoft also wanted to capture market share from Unix on other computing platforms, they needed a system design that was more portable than that of OS/2.
To this end, Microsoft began by developing and testing their new operating system for a non-x86 processor: an emulated version of the Intel i860. Alluding to the chip's codename, "N10", Microsoft codenamed their operating system NT OS/2. DEC preemptively sued Microsoft, alleging that they stole code from MICA for use in the new operating system. In an out-of-court settlement, Microsoft agreed to make NT OS/2 compatible with DEC's Alpha processor.
The development team originally estimated that development would be complete within 18 months. By April 1989, the NT OS/2 kernel could run inside the i860 emulator. However, the development team later determined that the i860 was unsuitable for the project. By December they had begun porting NT OS/2 to the MIPS R3000 processor instead, and completed the task in three months. Senior Microsoft executive Paul Maritz was targeting a release date in 1992, but the development schedule was uncertain. The company was eager to silence naysayers who speculated that NT wouldn't be on the market until 1994, and had planned to present the new OS at COMDEX in 1990.
As Windows NT In May 1990, Microsoft released Windows 3.0, a new version of its MS-DOS-based Windows desktop environment. Windows 3.0 sold well, and the resulting shift in Microsoft's marketing strategy eroded their partnership with IBM—who wanted Microsoft to concentrate solely on developing OS/2 as its primary platform as opposed to building their future business around Windows. Users and developers were unsure of whether to adopt Windows or OS/2 due to these uncertainties (a situation magnified by the fact that the operating systems were incompatible with each other at the API level), while Microsoft's resources were also being drained by the simultaneous development of multiple operating systems. In August 1990, as a response to the popularity of Windows 3.0, the NT OS/2 team decided to re-work the operating system to use an extended 32-bit port of the Windows API known as Win32. Win32 maintained the familiar structure of the 16-bit APIs used by Windows, which would allow developers to easily adapt their software for the new platform while maintaining a level of compatibility with existing software for Windows. With the shift to a Windows-like architecture, the operating system's shell was also changed from OS/2's Presentation Manager to Windows' Program Manager.
Due to these changes, NT was not presented at COMDEX 1990 as was originally planned. Neither the general public nor IBM knew about the transformation of NT OS/2 into Windows NT at the time. Although the companies did agree to a revised partnership where IBM and Microsoft would alternate developing major versions of OS/2 instead of collaborating on each version, IBM eventually learned of Microsoft's Windows NT plans in January 1991, and immediately ended the OS/2 partnership. IBM would solely develop OS/2 2.0 (as was planned under the amended version) and all future versions, without any further involvement from Microsoft.
In October 1991, Windows NT received its first public demonstration at COMDEX. In an effort to ensure software taking advantage of Windows NT was available upon its release (scheduled for late-1992), Microsoft also distributed a 32-bit software development kit to selected developers in attendance. The demonstration was positively received; PC Magazine called Windows NT "the modern reinvention of the operating system", but at the same time claimed that it was unlikely that the promised backward compatibility would be kept for the final release. In March 1992, Microsoft also released Win32s, which would allow Windows 3.1 to have partial compatibility with Windows NT programs for the purposes of developing software optimized for the platform.
At Microsoft's Win32 Professional Developers Conference in June 1992, Windows NT was demonstrated running on x86 and MIPS processors, while a beta version of Windows NT and an updated development kit were also made available. Concurrently, Microsoft announced a new version of its SQL Server product for Windows NT; Unix vendors feared that the software could be a killer app that would affect the market share of Unix systems. Concerns were also raised over NT's memory usage; while most computers of the era shipped with 4 megabytes of RAM, 16 MB was recommended for NTs. Due to the high cost of RAM at the time, critics thought that its high system requirements could affect the sales and adoption of Windows NT. Steps were taken to reduce its memory usage through methods such as paging.
Microsoft began releasing public beta builds of NT in October 1992, and a month later at COMDEX, a presentation focusing on third-party software for Windows NT was held. The final pre-release version of NT was released in March 1993, alongside the unveiling of the server version, LAN Manager for Windows NT. Although its stability and performance had improved, there were still fears that the OS could be released in an unfinished state or delayed further into 1993.
By extending the Windows brand and beginning NT at version 3.1, like Windows 3.1 which had established brand recognition and market share, Microsoft implied that consumers should expect a familiar user experience yet re-engineered.
Release Windows NT 3.1 and Windows NT 3.1 Advanced Server (so numbered to associate them with Windows 3.1) were released on July 26, 1993. At first, only the x86 and MIPS versions shipped; the DEC Alpha version followed in September. Microsoft sold the workstation version for , and the server version for . Ostensibly, the server price was meant to be a promotional discount offered only during the first six months of sale, but they never raised the retail price to the listed one—. 250 programmers wrote 5.6 million lines of code; the development cost . In the last year of development, the team fixed more than 30,000 bugs.
During the product's lifecycle, Microsoft published three service packs: Service Pack 1 was released on October 8, 1993; Service Pack 2 followed on January 24, 1994; and Service Pack 3's release date was October 29, 1994. The service packs were distributed on CD-ROM and floppy disk, and also through bulletin board systems (BBS), CompuServe, and the Internet. Microsoft terminated support for the operating system on December 31, 2000. Support for Windows NT 3.1 RTM (without a service pack) ended on January 8, 1994. Service Pack 1 support ended on April 24, 1994, and finally, Service Pack 2 support ended on January 29, 1995, only 1 year after general availability.
Windows NT 3.1 was localized into various languages. Besides English, it was available in Dutch, French, German, Japanese, Spanish and Swedish. The version for workstations, but not Windows NT 3.1 Server, was additionally available in Danish, Finnish, Italian, Norwegian and Portuguese.
Operating system goals