Tuesday, September 23, 2008

Early history of Windows

Early history: an expansion of MS-DOS


The first independent version of Microsoft Windows, version 1.0, released on 20 November 1985, lacked a degree of functionality and achieved little popularity. It was originally going to be called 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 extended MS-DOS, and shared the latter's inherent flaws and problems. The first version of Microsoft Windows includes a simple graphics painting program called Windows Paint, Windows Write, a simple word processor, and also includes the MS-DOS Executive, an appointment calendar, a cardfiler, a notepad, a clock, a control panel, a terminal, Clipboard and RAM driver. It also includes a game called Reversi.

Furthermore, legal challenges by Apple limited its functionality. For example, windows can only appear "tiled" on the screen; that is, they cannot overlap or overlie one another. Also, there is no trash can (place to store files prior to deletion), since Apple claimed ownership of the rights to that paradigm. Microsoft later removed both of these limitations by signing a licensing agreement.

Microsoft Windows version 2 came out on 9 December 1987, and proved slightly more popular than its predecessor. Much of the popularity for Windows 2.0 came by way of its inclusion as a "run-time version" with Microsoft's new graphical applications, Excel and Word for Windows. They can be run from MS-DOS, executing Windows for the duration of their activity, and closing down Windows upon exit.

Microsoft Windows received a major boost around this time when Aldus PageMaker appeared in a Windows version, having previously run only on Macintosh. Some computer historians date this, the first appearance of a significant and non-Microsoft application for Windows, as the beginning of the success of Windows.

Versions 2.0x uses the real-mode memory model, which confines it to a maximum of 1 megabyte of memory. In such a configuration, it can run under another multitasker like DESQview, which use the 286 Protected Mode.

Later, two new versions were released: Windows/286 2.1 and Windows/386 2.1. Like previous versions of Windows, Windows/286 2.1 uses the real-mode memory model, but was the first version to support the HMA. Windows/386 2.1 has a protected mode kernel with LIM-standard EMS emulation, the predecessor to XMS which would finally change the topology of IBM PC computing. All Windows and DOS-based applications at the time were real mode, running over the protected mode kernel by using the virtual 8086 mode, which was new with the 80386 processor.

Version 2.03, and later 3.0, faced challenges from Apple over its overlapping windows and other features Apple charged mimicked the "look and feel" of its operating system and "embodie[d] and generate[d] a copy of the Macintosh" in its OS. Judge William Schwarzer dropped all but 10 of the 189 charges that Apple had sued Microsoft with on 5 January 1989.


Success with Windows 3.0:


Windows 3.0 screenshot

Windows 3.0 screenshot

Microsoft Windows scored a significant success with Windows 3.0, released in 1990. In addition to improved capabilities given to native applications, Windows also allows a user to better multitask older MS-DOS based software compared to Windows/386, thanks to the introduction of virtual memory. It made PC compatibles serious competitors to the Apple Macintosh. This benefited from the improved graphics available on PCs by this time (by means of VGA video cards), and the Protected/Enhanced mode which allowed Windows applications to use more memory in a more painless manner than their DOS counterparts could. Windows 3.0 can run in any of Real, Standard, or 386 Enhanced modes, and is compatible with any Intel processor from the 8086/8088 up to 80286 and 80386. Windows 3.0 tries to auto detect which mode to run in, although it can be forced to run in a specific mode using the switches: /r (real mode), /s ("standard" 286 protected mode) and /3 (386 enhanced protected mode) respectively. This was the first version to run Windows programs in protected mode, although the 386 enhanced mode kernel was an enhanced version of the protected mode kernel in Windows/386.

Due to this backward compatibility, Windows 3.0 applications also must be compiled in a 16-bit environment, without ever using the full 32-bit capabilities of the 386 CPU.

A "multimedia" version, Windows 3.0 with Multimedia Extensions 1.0, was released several months later. This was bundled with "multimedia upgrade kits", comprising a CD-ROM drive and a sound card, such as the Creative Labs Sound Blaster Pro. This version was the precursor to the multimedia features available in Windows 3.1 and later, and was part of the specification for Microsoft's specification for the Multimedia PC.

The features listed above and growing market support from application software developers made Windows 3.0 wildly successful, selling around 10 million copies in the two years before the release of version 3.1. Windows 3.0 became a major source of income for Microsoft, and led the company to revise some of its earlier plans.

OS/2:


During the mid to late 1980s, Microsoft and IBM had cooperatively been developing OS/2 as a successor to DOS. OS/2 would take full advantage of the aforementioned Protected Mode of the Intel 80286 processor and up to 16MB of memory. OS/2 1.0, released in 1987, supported swapping and multitasking and allowed running of DOS executables.

A GUI, called the Presentation Manager (PM), was not available with OS/2 until version 1.1, released in 1988. Its API was incompatible with Windows. (Among other things, Presentation Manager placed X,Y coordinate 0,0 at the bottom left of the screen like Cartesian coordinates, while Windows put 0,0 at the top left of the screen like most other computer window systems.) Version 1.2, released in 1989, introduced a new file system, HPFS, to replace the FAT file system.

By the early 1990s, conflicts developed in the Microsoft/IBM relationship. They cooperated with each other in developing their PC operating systems, and had access to each others' code. Microsoft wanted to further develop Windows, while IBM desired for future work to be based on OS/2. In an attempt to resolve this tension, IBM and Microsoft agreed that IBM would develop OS/2 2.0, to replace OS/2 1.3 and Windows 3.0, while Microsoft would develop a new operating system, OS/2 3.0, to later succeed OS/2 2.0.

This agreement soon however fell apart, and the Microsoft/IBM relationship was terminated. IBM continued to develop OS/2, while Microsoft changed the name of its (as yet unreleased) OS/2 3.0 to Windows NT. Both retained the rights to use OS/2 and Windows technology developed up to the termination of the agreement; Windows NT, however, was to be written anew, mostly independently (see below).

After an interim 1.3 version to fix up many remaining problems with the 1.x series, IBM released OS/2 version 2.0 in 1992. This was a major improvement: it featured a new, object-oriented GUI, the Workplace Shell (WPS), that included a desktop and was considered by many to be OS/2's best feature. Microsoft would later imitate much of it in Windows 95. Version 2.0 also provided a full 32-bit API, offered smooth multitasking and could take advantage of the 4 gigabytes of address space provided by the Intel 80386. Still, much of the system still had 16-bit code internally which required, among other things, device drivers to be 16-bit code as well. This was one of the reasons for the chronic shortage of OS/2 drivers for the latest devices. Version 2.0 could also run DOS and Windows 3.0 programs, since IBM had retained the right to use the DOS and Windows code as a result of the breakup.


Windows 3.1 and NT:


A common Microsoft Windows logo (1992-1999)

A common Microsoft Windows logo (1992-1999)
Windows 3.1 start up screen

Windows 3.1 start up screen
Windows 3.11 screenshot

Windows 3.11 screenshot

In response to the impending release of OS/2 2.0, Microsoft developed Windows 3.1, which includes several minor improvements to Windows 3.0 (such as display of TrueType scalable fonts, developed jointly with Apple), but primarily consists of bugfixes and multimedia support. It also excludes support for Real mode, and only runs on an 80286 or better processor. Later Microsoft also released Windows 3.11, a touch-up to Windows 3.1 which includes all of the patches and updates that followed the release of Windows 3.1 in 1992. Around the same time, Microsoft released Windows for Workgroups (WfW), available both as an add-on for existing Windows 3.1 installations and in a version that included the base Windows environment and the networking extensions all in one package. Windows for Workgroups includes improved network drivers and protocol stacks, and support for peer-to-peer networking. One optional download for WfW was the "Wolverine" TCP/IP protocol stack, which allowed for easy access to the Internet through corporate networks. There are two versions of Windows for Workgroups, WfW 3.1 and WfW 3.11. Unlike the previous versions, Windows for Workgroups 3.11 only runs in 386 Enhanced mode, and requires at least an 80386SX processor.

All these versions continued version 3.0's impressive sales pace. Even though the 3.1x series still lacked most of the important features of OS/2, such as long file names, a desktop, or protection of the system against misbehaving applications, Microsoft quickly took over the OS and GUI markets for the IBM PC. The Windows API became the de-facto standard for consumer software.

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 1988 to create a portable version of OS/2, but Cutler created a completely new system instead. Cutler had been developing a follow-on to VMS at DEC called Mica, and when DEC dropped the project he brought the expertise and some engineers with him to Microsoft. DEC also believed he brought Mica's code to Microsoft and sued. Microsoft eventually paid $150 million U.S. and agreed to support DEC's Alpha CPU chip in NT.

Windows NT 3.1 (Microsoft marketing desired to make Windows NT appear to be a continuation of Windows 3.1) arrived in Beta form to developers at the July 1992 Professional Developers Conference in San Francisco. Microsoft announced at the conference its intentions to develop a successor to both Windows NT and Windows 3.1's replacement (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, and still, parts of Cairo have not made it into Windows as of today. Specifically, the WinFS subsystem, which was the much touted Object File System of Cairo, which had been put on hold for a while, but Microsoft further announced that they have discontinued WinFS and will gradually incorporate the technologies developed for WinFS in other products and technologies, notably, Microsoft SQL Server.

Driver support was lacking due to the increased programming difficulty in dealing with NT's superior hardware abstraction model. This problem plagued the NT line all the way through Windows 2000. Programmers complained that it was too hard to write drivers for NT, and hardware developers were not going to go through the trouble of developing drivers for a small segment of the market. Additionally, although allowing for good performance and fuller exploitation of system resources, it was also resource-intensive on limited hardware, and thus was only suitable for larger, more expensive machines. Windows NT would not work for private users because of its resource demands; moreover, its GUI was simply a copy of Windows 3.1's, which was inferior to the OS/2 Workplace Shell, so there was not a good reason to propose it as a replacement to Windows 3.1.

However, the same features made Windows NT perfect for the LAN server market (which in 1993 was experiencing a rapid boom, as office networking was becoming a commodity), as it enjoyed advanced network connectivity options, and the efficient NTFS file system. Windows NT version 3.51 was Microsoft's stake into this market, a large part of which would be won over from Novell in the following years.

One of Microsoft's biggest advances initially developed for Windows NT was new 32-bit API, to replace the legacy 16-bit Windows API. This API was called Win32, and from then on Microsoft referred to the older 16-bit API as Win16. Win32 API had three main implementations: one for Windows NT, one for Win32s (which was a subset of Win32 which could be used on Windows 3.1 systems), and one for Chicago. Thus Microsoft sought to ensure some degree of compatibility between the Chicago design and Windows NT, even though the two systems had radically different internal architectures. Windows NT was the first Windows operating system based on a hybrid kernel.


Windows 95:


Windows 95 Logo
Microsoft Windows 95 screenshot

Microsoft Windows 95 screenshot

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 like 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. This, and the fact that the numerous design flaws had to be carried over from the earlier Windows versions, eventually began to impact on the operating system's efficiency and stability.

Microsoft marketing adopted Windows 95 as the product name for Chicago when it was released on 24 August 1995. Microsoft had a double gain from its release: first it made it impossible for consumers to run Windows 95 on a cheaper, non-Microsoft DOS; secondly, although traces of DOS were never completely removed from the system, and a version of DOS would be loaded briefly as a part of the booting process, Windows 95 applications ran solely in 386 Enhanced Mode, with a flat 32-bit address space and virtual memory. These features make it possible for Win32 applications to address up to 2 gigabytes of virtual RAM (with another 2GB reserved for the operating system), and in theory prevents them from inadvertently corrupting the memory space of other Win32 applications. In this respect the functionality of Windows 95 moved closer to Windows NT, although Windows 95/98/ME does not support more than 512 megabytes of physical RAM without obscure system tweaks.

IBM continued to market OS/2, producing later versions in OS/2 3.0 and 4.0 (also called Warp). Responding to complaints about OS/2 2.0's high demands on computer hardware, version 3.0 was significantly optimized both for speed and size. Before Windows 95 was released, OS/2 Warp 3.0 was even shipped preinstalled with several large German hardware vendor chains. However, with the release of Windows 95, OS/2 began to lose market share.

It is probably impossible to nail down a specific reason why OS/2 failed to gain much market share. While OS/2 continued to run Windows 3.1 applications, it lacked support for anything but the Win32s subset of Win32 API (see above). Unlike with Windows 3.1, IBM did not have access to the source code for Windows 95 and was unwilling to commit the time and resources to emulate the moving target of the Win32 API. IBM also introduced OS/2 into the United States v. Microsoft case, blaming unfair marketing tactics on Microsoft's part, but many people would probably agree that IBM's own marketing problems and lack of support for developers contributed at least as much to the failure.

Microsoft released 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). This product was sold under the name Windows 97 in some countries in Europe.

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


NT 4.0:


Windows NT 4.0 Server screenshot

Windows NT 4.0 Server screenshot

Microsoft released Windows NT 4.0, which features the new Windows 95 interface on top of the Windows NT kernel. (a patch was available for developers to make NT 3.51 use the new UI, but it was quite buggy).

Windows NT 4.0 came in four versions:

  • Windows NT 4.0 Workstation
  • Windows NT 4.0 Server
  • Windows NT 4.0 Server, Enterprise Edition (includes support for 8-way SMP and clustering)
  • Windows NT 4.0 Terminal Server

Windows 98 logo

Windows 98 logo

Windows 98 screenshot.

Windows 98 screenshot.

On 25 June 1998, Microsoft released Windows 98, which was widely regarded as a minor revision of Windows 95, but generally found to be more stable and reliable than its 1995 predecessor. It includes 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 is far superior to the token, sketchy support provided by the OEM editions of Windows 95. It also controversially integrated the Internet Explorer browser into the Windows GUI and Windows Explorer file manager, prompting the opening of the United States v. Microsoft case, dealing with the question whether Microsoft was abusing its hold on the PC operating system market to unfairly compete with companies such as Netscape.

In 1999, Microsoft released Windows 98 Second Edition, an interim release whose most notable feature was the addition of Internet Connection Sharing, which was a form of network address translation, allowing several machines on a LAN (Local Area Network) to share a single Internet connection. 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.


Windows 2000:




Windows 2000 screenshot

Windows 2000 screenshot
Windows 2000 logo

Windows 2000 logo

Microsoft released Windows 2000, known during its development cycle as Windows NT 5.0, in February 2000. It was successfully deployed both on the server and the workstation markets. Amongst Windows 2000's most significant new features was Active Directory, a near-complete replacement of the NT 4.0 Windows Server domain model, which built on industry-standard technologies like DNS, LDAP, and Kerberos to connect machines to one another. Terminal Services, previously only available as a separate edition of NT 4, was expanded to all server versions. A number of features from Windows 98 were incorporated as well, such as an improved Device Manager, Windows Media Player, and a revised DirectX that made it possible for the first time for many modern games to work on the NT kernel. Windows 2000 is also the last NT-kernel Windows operating system to lack Product Activation.

While Windows 2000 upgrades were available for Windows 95 and Windows 98, it was not intended for home users.[1] It lacked device drivers for many common consumer devices such as scanners and printers[citation needed]. The original release of Windows 2000 had a buggy and counterintuitive installation procedure[citation needed]; this was not fully rectified until Service Pack 4 in June, 2003, after XP had been released.

Windows 2000 was available in six editions:

  • Windows 2000 Professional
  • Windows 2000 Server
  • Windows 2000 Advanced Server
  • Windows 2000 Datacenter Server
  • Windows 2000 Advanced Server Limited Edition
  • Windows 2000 Datacenter Server Limited Edition

WindowsMillenniumEdition(Me):


Windows Me logo

Windows Me logo
Windows Millennium Edition screenshot

Windows Millennium Edition screenshot

In September 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. System Restore was a notable feature that made its way into Windows XP. 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, (System Restore was an exception). As a result, Windows Me was not acknowledged as a unique Operating System along the lines of 95 or 98. Windows Me was widely criticised for serious stability issues, and for lacking real mode DOS support, to the point of being referred to as the "Mistake Edition". Windows Me was the last operating system to be based on the Windows 9x (monolithic) kernel and MS-DOS. It is also the last 32-bit release of Microsoft Windows that did not include Product Activation.

Windows XP:

Windows XP screenshot - showing the Sample Pictures folder, Sample Music folder, and Control Panel, with the blue Luna scheme and Bliss desktop.

Windows XP screenshot - showing the Sample Pictures folder, Sample Music folder, and Control Panel, with the blue Luna scheme and Bliss desktop.
The Windows logo, redesigned with the release of Windows XP, used until 4 December 2006.

The Windows logo, redesigned with the release of Windows XP, used until 4 December 2006.

In 2001, Microsoft introduced Windows XP (codenamed "Whistler"). The merging of the Windows NT/2000 and Windows 95/98/Me lines was finally achieved with Windows XP. Windows XP uses the Windows NT 5.1 kernel, marking the entrance of the Windows NT core to the consumer market, to replace the aging 16/32-bit branch. The initial release met with considerable criticism, particularly in the area of security, leading to the release of three major Service Packs. Windows XP SP1 was released in September of 2002, SP2 came out in August, 2004 and SP3 came out in April, 2008. Service Pack 2 provided significant improvements and encouraged widespread adoption of XP among both home and business users. Windows XP was the current edition longer than any other version of Windows, from 2001 all the way to 2007 when Windows Vista was released to consumers. The Windows XP line of operating systems was succeeded by Windows Vista on 30 January 2007.

Windows XP is available in a number of versions:

  • "Windows XP Home Edition", for home desktops and laptops (notebooks)
  • "Windows XP Home Edition N", as above, but without a default installation of Windows Media Player, as mandated by a European Union ruling
  • "Windows XP Professional", for business and power users
  • "Windows XP Professional N", as above, but without a default installation of Windows Media Player, as mandated by a European Union ruling
  • Windows XP Media Center Edition (MCE), released in November 2002 for desktops and notebooks with an emphasis on home entertainment
    • Windows XP Media Center Edition 2003
    • Windows XP Media Center Edition 2004
    • Windows XP Media Center Edition 2005, released on 12 October 2004.
  • "Windows XP Tablet PC Edition", for tablet PCs (PCs with touch screens)
    • Windows XP Tablet PC Edition 2005
  • Windows XP Embedded, for embedded systems
  • "Windows XP Starter Edition", for new computer users in developing countries
  • Windows XP Professional x64 Edition, released on 25 April 2005 for home and workstation systems utilizing 64-bit processors based on the x86-64 instruction set developed by AMD as AMD64; Intel calls their version Intel 64)
  • Windows XP 64-bit Edition, is a version for Intel's Itanium line of processors; maintains 32-bit compatibility solely through a software emulator. It is roughly analogous to Windows XP Professional in features. It was discontinued in September 2005 when the last vendor of Itanium workstations stopped shipping Itanium systems marketed as "Workstations".
    • Windows XP 64-bit Edition 2003, based on the Windows NT 5.2 codebase.

    WindowsServer2003:



Windows Server 2003 desktop and Start menu.

Windows Server 2003 desktop and Start menu.


On 24 April 2003 Microsoft launched Windows Server 2003, a notable update to Windows 2000 Server encompassing many new security features, a new "Manage Your Server" wizard that simplifies configuring a machine for specific roles, and improved performance. It has the version number NT 5.2. A few services not essential for server environments are disabled by default for stability reasons, most noticeable are the "Windows Audio" and "Themes" services; Users have to enable them manually to get sound or the "Luna" look as per Windows XP. The hardware acceleration for display is also turned off by default, users have to turn the acceleration level up themselves if they trust the display card driver.

In December 2005, Microsoft released Windows Server 2003 R2, which is actually Windows Server 2003 with SP1 (Service Pack 1) plus an add-on package. Among the new features are a number of management features for branch offices, file serving, printing and company-wide identity integration.

Windows Server 2003 is available in six editions:

  • Web Edition (32-bit)
  • Standard Edition (32 and 64-bit)
  • Enterprise Edition (32 and 64-bit)
  • Datacenter Edition (64-bit)
  • Small Business Server (32-bit)
  • Storage Server (OEM channel only)

WindowsVista:


Windows Vista, showing its new Aero Glass interface, Welcome Center and Start menu.

Windows Vista, showing its new Aero Glass interface, Welcome Center and Start menu.
Windows Vista logo.

Windows Vista logo.

The current client version of Windows, Windows Vista (codenamed Longhorn) was released on 30 November 2006[1] to business customers, with consumer versions following on 30 January 2007. Windows Vista intends to have enhanced security by introducing a new restricted user mode called User Account Control, replacing the "administrator-by-default" philosophy of Windows XP. Vista also features new graphics features, the Windows Aero GUI, new applications (such as Windows Calendar, Windows DVD Maker and some new games including Chess, Mahjong, and Purble Place), a revised and more secure version of Internet Explorer, a new version of Windows Media Player, and a large number of underlying architectural changes.

Windows Vista ships in several editions:

  • Starter (only available in developing countries)
  • Home Basic
  • Home Premium
  • Business
  • Enterprise (only available to large businesses and enterprises)
  • Ultimate (combines both Home Premium and Enterprise)

All editions (except Starter edition) are available in both 32-bit and 64-bit versions. The biggest advantage of the 64-bit version is breaking the 4 gigabyte memory barrier, which 32-bit computers cannot fully access. In the first year after Vista's release, most installations were still 32-bit, due to poor driver support of the 64-bit version.


WindowsServer:2008


Windows Server 2008, Windows Server 2008 screenshot

Windows Server 2008, Windows Server 2008 screenshot
Windows Server 2008, released on 27 February 2008, was originally known as Windows Server Codename "Longhorn". Windows Server 2008 builds on the technological and security advances first introduced with Windows Vista, and is significantly more modular than its predecessor, Windows Server 2003.






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