Windows 9x

Windows 9x is a generic term referring to a series of Microsoft Windows computer operating systems produced from 1995 to 2000, which were based on the Windows 95 kernel and its underlying foundation of MS-DOS, both of which were updated in subsequent versions. The first version in the 9x series was Windows 95, which was succeeded by Windows 98 and then Windows Me, which was the last version of Windows on the 9x line.

Windows 9x is predominantly known for its use in desktops. In 1998, Windows made up 82% of operating system market share.

Internal release versions for versions of Windows 9x are 4.x. The internal versions for Windows 95, 98, and Me are 4.0, 4.1, and 4.9, respectively. Previous MS-DOS based versions of Windows used version numbers of 3.2 or lower. Windows NT, which was aimed at professional users such as networks and businesses, used a similar but separate version number between 3.1 and 4.0. All editions of Windows from Windows XP onwards are based on the Windows NT codebase.

History
See also: History of Microsoft Windows

Windows prior to 95
The first independent version of Microsoft Windows, version 1.0, released on November 20, 1985, achieved little popularity. Its name was initially "Interface Manager", but Rowland Hanson, the head of marketing at Microsoft, convinced the company that the name Windows would be more appealing to consumers. Windows 1.0 was not a complete operating system, but rather an "operating environment" that extended MS-DOS. Consequently, it shared the inherent flaws and problems of MS-DOS.

The second installment of Microsoft Windows, version 2.0, was released on December 9, 1987, and used the real-mode memory model, which confined it to a maximum of 1 megabyte of memory. In such a configuration, it could run under another multitasking system like DESQview, which used the 286 Protected Mode.

Microsoft Windows scored a significant success with Windows 3.0, released in 1990. In addition to improved capabilities given to native applications, Windows also allowed users to better multitask older MS-DOS based software compared to Windows/386, thanks to the introduction of virtual memory.

Microsoft developed Windows 3.1, which included several minor improvements to Windows 3.0, but primarily consisted of bugfixes and multimedia support. It also excluded support for Real mode, and only ran on an Intel 80286 or better processor. Later Microsoft also released Windows 3.11, a touch-up to Windows 3.1 which included all of the patches and updates that followed the release of Windows 3.1 in 1992.

Meanwhile, Microsoft continued to develop Windows NT. The main architect of the system was Dave Cutler, one of the chief architects of VMS at Digital Equipment Corporation (later purchased by Compaq, now part of Hewlett-Packard). Microsoft hired him in August 1988 to create a successor to OS/2, but Cutler created a completely new system instead.

Microsoft announced at its 1991 Professional Developers Conference its intentions to develop a successor to both Windows NT and Windows 3.1's replacement (Windows 95, code-named Chicago), which would unify the two into one operating system. This successor was codenamed Cairo. In hindsight, Cairo was a much more difficult project than Microsoft had anticipated and, as a result, NT and Chicago would not be unified until Windows XP.

Windows 95
Main article: Windows 95

After Windows 3.11, Microsoft began to develop a new consumer oriented version of the operating system code-named Chicago. Chicago was designed to have support for 32-bit preemptive multitasking, that of which was available in OS/2 and Windows NT, although a 16-bit kernel would remain for the sake of backward compatibility. The Win32 API first introduced with Windows NT was adopted as the standard 32-bit programming interface, with Win16 compatibility being preserved through a technique known as "thunking". A new GUI was not originally planned as part of the release, although elements of the Cairo user interface were borrowed and added as other aspects of the release (notably Plug and Play) slipped.

Microsoft did not change all of the Windows code to 32-bit, parts of it remained 16-bit (albeit not directly using real mode) for reasons of compatibility, performance and development time. Additionally it was necessary to carry over design decisions from earlier versions of Windows for reasons of backwards compatibility, even if these design decisions no longer matched a more modern computing environment. These factors immediately began to impact the operating system's efficiency and stability.

Microsoft marketing adopted Windows 95 as the product name for Chicago when it was released on August 24, 1995.

Microsoft went on to release five different versions of Windows 95:


 * Windows 95 - original release
 * Windows 95 A - included Windows 95 OSR1 slipstreamed into the installation.
 * Windows 95 B - (OSR2) included several major enhancements, Internet Explorer (IE) 3.0 and full FAT32 file system support.
 * Windows 95 B USB - (OSR2.1) included basic USB support.
 * Windows 95 C - (OSR2.5) included all the above features, plus IE 4.0. This was the last 95 version produced.

OSR2, OSR2.1, and OSR2.5 were not released to the general public, rather, they were available only to OEMs that would preload the OS onto computers. Some companies sold new hard drives with OSR2 preinstalled (officially justifying this as needed due to the hard drive's capacity).

The first Microsoft Plus! add-on pack was sold for Windows 95.

Windows 98
Main article: Windows 98

On June 25, 1998, Microsoft released Windows 98. It included new hardware drivers and better support for the FAT32 file system which allows support for disk partitions larger than the 2 GB maximum accepted by Windows 95. The USB support in Windows 98 was more robust than the basic support provided by the OEM editions of Windows 95. It also controversially integrated the Internet Explorer 4 browser into the Windows GUI and Windows Explorer file manager.

On May 5, 1999, Microsoft released Windows 98 Second Edition, an interim release whose notable features were the addition of Internet Connection Sharing and improved WDM audio and modem support. Internet Connection Sharing is a form of network address translation, allowing several machines on a LAN (Local Area Network) to share a single Internet connection. Windows 98 Second Edition has certain improvements over the original release. Hardware support through device drivers was increased. Many minor problems present in the original Windows 98 were found and fixed which make it, according to many, the most stable release of Windows 9x family—to the extent that commentators used to say that Windows 98's beta version was more stable than Windows 95's final (gamma) version.

Windows ME
Main article: Windows ME

On September 14, 2000, Microsoft introduced Windows Me (Millennium Edition), which upgraded Windows 98 with enhanced multimedia and Internet features. It also introduced the first version of System Restore, which allowed users to revert their system state to a previous "known-good" point in the case of system failure. The first version of Windows Movie Maker was introduced as well.

Windows Me was conceived as a quick one-year project that served as a stopgap release between Windows 98 and Windows XP. Many of the new features were available from the Windows Update site as updates for older Windows versions. As a result, Windows Me was not acknowledged as a distinct operating system along the lines of 95 or 98, and is often included in the Windows 9x series.

Windows Me was criticized by users for its instability and unreliability, due to frequent freezes and crashes. A PC World article dubbed Windows Me the "Mistake Edition" and placed it 4th in their "Worst Tech Products of All Time" feature.

The inability of users to easily boot into real mode MS-DOS, as in Windows 95 and 98, led users to quickly learn how to hack their Windows Me installations to provide the needed service.

Decline
The release of Windows 2000 marked a shift in the user experience between the Windows 9x series and the Windows NT series. Windows NT 4.0 suffered from a lack of support for USB, Plug and Play, and DirectX, preventing its users from playing contemporary games, whereas Windows 2000 featured an updated user interface, and better support for both Plug and Play and USB.

The release of Windows XP confirmed the change of direction for Microsoft, bringing the consumer and business operating systems together.

One by one, support for the Windows 9x series ended, and Microsoft stopped selling the software to end users, then later to OEMs. By March 2004, it was impossible to purchase any versions of the Windows 9x series.

End of service life
Microsoft continued to support the use of the Windows 9x series until July 11, 2006, when extended support ended for Windows 98, Windows 98 Second Edition (SE), and Windows Millennium Edition (Me) (extended support for Windows 95 ended on December 31, 2001).

Microsoft DirectX, a set of standard gaming APIs, stopped being updated on Windows 95 at Version 8.0a. The last version of DirectX supported for Windows 98 and Me is 9.0c.

Support for Microsoft Internet Explorer running on any Windows 9x system has also since ended. Internet Explorer 5.5 with Service Pack 2 is the last version of Internet Explorer compatible with Windows 95 and Internet Explorer 6 with Service Pack 1 is the last version compatible with Windows 98 and Me. Internet Explorer 7, the first major update to Internet Explorer 6 in half a decade, was only available for Windows XP SP2 and Windows Vista.

The growing number of important updates caused by the end of service life of these pieces of software have slowly made Windows 9x even less practical for everyday use. Today, even open source projects such as Mozilla Firefox will not run on Windows 9x without rework.

RetroZilla is a fork of Gecko 1.8.1 aimed at bringing "improved compatibility on the modern web" for versions of Windows as old as Windows 95 and NT 4.0. The latest version, 2.2, was released in February 2019 and added support for TLS 1.2.