Microsoft introduced an operating environment named Windows on November 20, 1985 as a graphical operating system shell for MS-DOS in response to the growing interest in graphical user interfaces (GUI).[2] Microsoft Windows came to dominate the world's personal computer market with over 90% market share, overtaking Mac OS, which had been introduced in 1984.
As of April 2013, the most recent versions of Windows for personal computers, mobile devices, server computers and embedded devices are respectively Windows 8, Windows Phone 8, Windows Server 2012 and Windows Embedded 8 Industry.
Main article: History of Microsoft Windows
See also: List of Microsoft Windows versions
The term Windows collectively describes any or all of several generations of Microsoft operating system products. These products are generally categorized as follows:
Early versions
Main articles: Windows 1.0, Windows 2.0, and Windows 2.1x
Windows 2.0 was released in December 1987 and was more popular than its predecessor. It features several improvements to the user interface and memory management.[3] Windows 2.03 changed the OS from tiled windows to overlapping windows. The result of this change led to Apple Computer filing a suit against Microsoft alleging infringement on Apple's copyrights.[4][5] Windows 2.0 also introduced more sophisticated keyboard shortcuts and could make use of expanded memory.
Windows 2.1 was released in two different versions: Windows/286 and Windows/386. Windows/386 employs the virtual 8086 mode of Intel 80386 to multitask several DOS programs and the paged memory model to emulate expanded memory using available extended memory. Windows/286, in spite of its name, runs on both Intel 8086 and Intel 80286. It runs in real mode but can make use of the high memory area.
In addition to full Windows-packages, there were runtime-only versions that shipped with early Windows software from third parties and made it possible to run their Windows software on MS-DOS and without the full Windows feature set.
The early versions of Windows are often thought of as graphical shells, mostly because they ran on top of MS-DOS and use it for file system services.[6] However, even the earliest Windows versions already assumed many typical operating system functions; notably, having their own executable file format and providing their own device drivers (timer, graphics, printer, mouse, keyboard and sound). Unlike MS-DOS, Windows allowed users to execute multiple graphical applications at the same time, through cooperative multitasking. Windows implemented an elaborate, segment-based, software virtual memory scheme, which allows it to run applications larger than available memory: code segments and resources are swapped in and thrown away when memory became scarce; data segments moved in memory when a given application had relinquished processor control.
Windows 3.0 and 3.1
Main articles: Windows 3.0 and Windows 3.1x
Windows 3.1, made generally available on March 1, 1992, featured a facelift. In August 1993, Windows for Workgroups, a special version with integrated peer-to-peer networking features and a version number of 3.11, was released. It was sold along Windows 3.1. Support for Windows 3.1 ended on December 31, 2001.[9]
Windows 9x
Main articles: Windows 95, Windows 98, and Windows ME
Microsoft published several[quantify] OEM Service Releases (OSR) of Windows 95, each of which was roughly equivalent to a service pack. Mainstream support for Windows 95 ended on December 31, 2000 and extended support for Windows 95 ended on December 31, 2001.[10]
Next in the consumer line is Microsoft Windows 98, released on June 25, 1998. It was followed with the release of Windows 98 Second Edition (often shortened to Windows 98 SE) in May 1999. Mainstream support for Windows 98 ended on June 30, 2002 and extended support for Windows 98 ended on July 11, 2006.[11][further explanation needed]
In February 2000, Windows 2000 was released, followed by Windows ME in September 2000. In spite of its name, Windows 2000 is a successor of Windows NT 4.0 and is a member of Windows NT family, which was produced separately along with Windows 3.x and Windows 9x and marketed in enterprise sector for workstations and server computers. The successor of Windows 98 is Windows ME (Windows Millennium Edition), which is developed based on the same core as Windows 98, but adopted some aspects of Windows 2000 and removed the "boot in DOS mode" option. Windows ME implemented Universal Plug and Play and added a new feature called System Restore, allowing users to revert their computers' settings back to an earlier date. Windows ME was heavily criticized for slowness, freezes and hardware problems. PC World called Windows ME one of the worst operating systems Microsoft ever released.[12]
Windows NT family
Main article: Windows NT
In July 1993, Microsoft released Windows NT
based on a new kernel. The NT family of Windows systems was fashioned
and marketed for higher reliability business use, considered to be the
professional OS. The first release was Windows NT 3.1 (1993), numbered "3.1" to match the consumer Windows version, which was followed by Windows NT 3.5 (1994), Windows NT 3.51 (1995), Windows NT 4.0 (1996) and Windows 2000 (2000). Windows NT was the first Windows version to utilize preemptive multitasking.[citation needed]
Windows NT 4.0 was the first in this line to implement the "Windows 95"
user interface (and the first to include Windows 95's built-in 32-bit
runtimes).Microsoft released Windows 2000 as part of the NT line in February 2000. During 2004 part of the source code for Windows 2000 was leaked onto the Internet. Windows 2000 is the last NT-based Windows release that does not include Microsoft Product Activation. After Windows 2000, the Windows NT family was split into two lines: A client line, including Windows XP and its successors, consists of operating systems produced for installation on client computers, such as workstations, home computers, laptops, tablet computers and media centers. A Windows Server line, including Windows Server 2003 and it successors, consists of operating systems produced for server computers. Later, a third line for embedded systems was added with the introduction of Windows Embedded.
Windows XP, Vista and 7
Microsoft moved to combine their consumer and business operating systems with Windows XP that was released on October 25, 2001. Windows XP is built on the Windows NT kernel, retooled to also function as a home operating system. This new version was widely praised in computer magazines.[13]XP shipped in two distinct editions, "Home" and "Professional", the former lacking many of the superior security and networking features of the Professional edition. Additionally, the first "Media Center" edition was released in 2002,[14] with an emphasis on support for DVD and TV functionality including program recording and a remote control. A niche market versions for tablet PCs was also released. Mainstream support for Windows XP ended on April 14, 2009. Extended support will continue until April 8, 2014.[15]
After Windows 2000, they diverged release schedules for server operating systems. In April 2003, Windows Server 2003 was introduced, replacing the Windows 2000 line of server products with a number of new features and a strong focus on security; this was followed in December 2005 by Windows Server 2003 R2.
After a lengthy development process, Windows Vista was released on November 30, 2006 for volume licensing and January 30, 2007 for consumers. It contains a number of new features, from a redesigned shell and user interface to significant technical changes, with a particular focus on security features. It is available in a number of different editions, and has been subject to some criticism. Vista's server counterpart, Windows Server 2008 was released in early 2008.
On July 22, 2009, Windows 7 and Windows Server 2008 R2 were released as RTM (release to manufacturing) while the former was released to the public 3 months later on October 22, 2009. Unlike its predecessor, Windows Vista, which introduced a large number of new features, Windows 7 was intended to be a more focused, incremental upgrade to the Windows line, with the goal of being compatible with applications and hardware with which Windows Vista was already compatible.[16] Windows 7 has multi-touch support, a redesigned Windows shell with a new taskbar, referred to as the Superbar, a home networking system called HomeGroup,[17] and performance improvements.
Multilingual support: IMEs and LIPs
There are three main issues involved in making English-language Windows multilingual: (1) some languages require an Input Method Editor (IME) to enter text, (2) many users will want application menus (such as MS Office menus) to display in their own language, and they may also want to use a keyboard that matches the normal keyboard layout and marking for their own language, and (3) some users will want Windows menus and messages to display in their own language, i.e. they will want to switch from an English Windows environment to another language.For languages like Italian, Spanish, French and German, (2) alone may suffice. For languages like Chinese, Japanese, and Korean (CJK), an IME (1) is also required. This is bundled with the corresponding language version of Windows, but is also available as a separate download for English Windows, as described below; (1) and (2) can be essentially free (apart from the custom keyboard). For some languages, (3), multilingual support for Windows, is a free download for Windows XP and later—but it requires Windows 7 Ultimate or better for languages such as Chinese, Japanese, and Korean.
(1) After releasing Chinese, Japanese, and Korean bundles of Office 2010 and IME 2010, Microsoft made IME 2010 available as a free upgrade for users of the earlier IME versions of Windows. Microsoft later made these Chinese, Japanese, and Korean IME versions available free to users of Windows XP and later, including English Windows XP (but now says that users should own some version of MS Office).[18] Each IME package enables the entering of text in the corresponding language; necessary fonts may be bundled with it (or supplementary fonts offered with the corresponding version of Office).
(2) Microsoft now also offers Language Interface Packs (LIPs) for MS Office. Some LIPs are free;[19] some "Language Packs" (such as the CJK ones) are sold separately and may include spelling and grammar checking tools.[20] (Recent application software from some companies may support two or more popular languages).
(3) Microsoft now also offers Language Interface Packs (LIPs) that allow users to view Windows menus, dialog boxes, and other user interface items in their preferred language. These are free; most are for English Windows (XP and later)—however, Chinese, Japanese, and Korean LIP downloads require Windows 7 Ultimate or Enterprise.[21] These LIPs include IMEs where applicable.
Windows 8
Windows 8, the successor to Windows 7, was released to the market on 26 October 2012. Windows 8 has been designed to be used on both tablets and the conventional PC. The Microsoft Surface tablet was released alongside Windows 8, as a competitor to the Apple iPad and Android tablets. Microsoft Surface is available in two editions, Surface with Windows RT and Surface with Windows 8 Pro, aimed at designers and other work-based users. The Surface RT runs a limited version of Windows 8, Windows RT, and will not run many classic Windows desktop applications, as users can download new applications from the Windows App Store. However, the Surface Pro, released on February 9, 2013, has a full desktop operating system capable of running all classic desktop applications. See Microsoft Surface for more information. Windows 8 was released to manufacturing on 1 August 2012, with a build of 6.2.9200. It is available for purchase in two versions, Windows 8 and Windows 8 Pro.For the first time since Windows 95, the Start button is no longer available on the taskbar. It has been replaced with the Start screen and can be triggered by clicking the bottom-left corner of the screen and by clicking Start in the Charms or by pressing the Windows key on the keyboard. However, there are many third-party solutions such as Stardock Start8 and Classic Shell, that do bring back the Windows 7 style start menu. See List of Start Menu replacements for Windows 8 for more information.
In February 2013, it was reported that an update to Windows 8, codenamed Windows Blue, had completed the first milestone, indicating development is approximately halfway complete.[22] A leaked alpha version of Windows Blue has since hit the Internet.[23][24][25][26]
Platform support
Windows NT included support for several different platforms before the x86-based personal computer became dominant in the professional world. Versions of NT from 3.1 to 4.0 variously supported PowerPC, DEC Alpha and MIPS R4000, some of which were 64-bit processors, although the operating system treated them as 32-bit processors. However, Microsoft dropped support from the aforementioned in Windows 2000, which only supported the third generation x86 (known as IA-32) or newer in 32-bit mode. IA-32 is still supported in the client line of Window NT family, although the Windows Server line has ceased IA-32 support with the release of Windows Server 2008 R2.With the introduction of the Intel Itanium architecture (IA-64), Microsoft released new versions of Windows to support it. Itanium versions of Windows XP and Windows Server 2003 were released at the same time as their mainstream x86 counterparts. Microsoft dropped support for the Itanium version of Windows XP in 2005 and ceased to support it in all subsequent client operating system but continued to support it in Windows Server line until Windows Server 2012. Windows Server 2008 R2 was the last Windows operating system to support Itanium architecture.
On April 25, 2005, Microsoft released Windows XP Professional x64 Edition and Windows Server 2003 x64 Editions to support the x86-64 (or simply x64), the eighth generation of x86 architecture. Windows Vista was the first client version of Windows NT to be released simultaneously in IA-32 and x64 editions. x64 is still supported.
An edition of Windows 8 known as Windows RT is specifically created for computers with ARM architecture.
Windows CE
Main articles: Windows CE and Windows Phone
Windows CE was used in the Dreamcast along with Sega's own proprietary OS for the console. Windows CE was the core from which Windows Mobile was derived. Its successor, Windows Phone 7, was based on components from both Windows CE 6.0 R3 and Windows CE 7.0. Windows Phone 8 however, is based on the same NT-kernel as Windows 8.
Windows Embedded Compact is not to be confused with Windows XP Embedded or Windows NT 4.0 Embedded, modular editions of Windows based on Windows NT kernel.
Timeline of releases
Main article: Timeline of Microsoft Windows
| [show]Timeline of releases |
|---|
Main article: Usage share of operating systems
| Source | Net Market Share[29] | Global Stats[30] | W3Counter[31] |
|---|---|---|---|
| Date | February 2013 | February 2013 | February 2013 |
| All versions | 91.63% | 85.86% | 74.28% |
| Windows 7 | 44.55% | 52.46% | 43.69% |
| Windows XP | 38.99% | 23.87% | 22.59% |
| Windows Vista | 5.17% | 6.37% | 5.28% |
| Windows 8 | 2.79% | 3.16% | 2.72% |
| Windows 2000 | 0.06% | — | — |
| Windows NT 4.0 | 0.06% | — | — |
| Windows 98 | 0.01% | — | — |
Security
Consumer versions of Windows were originally designed for ease-of-use on a single-user PC without a network connection, and did not have security features built in from the outset.[32] However, Windows NT and its successors are designed for security (including on a network) and multi-user PCs, but were not initially designed with Internet security in mind as much, since, when it was first developed in the early 1990s, Internet use was less prevalent.[33]These design issues combined with programming errors (e.g. buffer overflows) and the popularity of Windows means that it is a frequent target of computer worm and virus writers. In June 2005, Bruce Schneier's Counterpane Internet Security reported that it had seen over 1,000 new viruses and worms in the previous six months.[34] In 2005, Kaspersky Lab found around 11,000 malicious programs—viruses, Trojans, back-doors, and exploits written for Windows.[35]
Microsoft releases security patches through its Windows Update service approximately once a month (usually the second Tuesday of the month), although critical updates are made available at shorter intervals when necessary.[36] In versions of Windows after and including Windows 2000 SP3 and Windows XP, updates can be automatically downloaded and installed if the user selects to do so. As a result, Service Pack 2 for Windows XP, as well as Service Pack 1 for Windows Server 2003, were installed by users more quickly than it otherwise might have been.[37]
While the Windows 9x series offered the option of having profiles for multiple users, they had no concept of access privileges, and did not allow concurrent access; and so were not true multi-user operating systems. In addition, they implemented only partial memory protection. They were accordingly widely criticised for lack of security.
The Windows NT series of operating systems, by contrast, are true multi-user, and implement absolute memory protection. However, a lot of the advantages of being a true multi-user operating system were nullified by the fact that, prior to Windows Vista, the first user account created during the setup process was an administrator account, which was also the default for new accounts. Though Windows XP did have limited accounts, the majority of home users did not change to an account type with fewer rights – partially due to the number of programs which unnecessarily required administrator rights – and so most home users ran as administrator all the time.
Windows Vista changes this[38] by introducing a privilege elevation system called User Account Control. When logging in as a standard user, a logon session is created and a token containing only the most basic privileges is assigned. In this way, the new logon session is incapable of making changes that would affect the entire system. When logging in as a user in the Administrators group, two separate tokens are assigned. The first token contains all privileges typically awarded to an administrator, and the second is a restricted token similar to what a standard user would receive. User applications, including the Windows Shell, are then started with the restricted token, resulting in a reduced privilege environment even under an Administrator account. When an application requests higher privileges or "Run as administrator" is clicked, UAC will prompt for confirmation and, if consent is given (including administrator credentials if the account requesting the elevation is not a member of the administrators group), start the process using the unrestricted token.[39]
File permissions
All Windows versions from Windows NT 3 have been based on a file system permission system referred to as AGLP (Accounts, Global, Local, Permissions) AGDLP which in essence where file permissions are applied to the file/folder in the form of a 'local group' which then has other 'global groups' as members. These global groups then hold other groups or users depending on different Windows versions used. This system varies from other vendor products such as Linux and NetWare due to the 'static' allocation of permission being applied directory to the file or folder. However using this process of AGLP/AGDLP/AGUDLP allows a small number of static permissions to be applied and allows for easy changes to the account groups without reapplying the file permissions on the files and folders.Windows Defender
On January 6, 2005, Microsoft released a Beta version of Microsoft AntiSpyware, based upon the previously released Giant AntiSpyware. On February 14, 2006, Microsoft AntiSpyware became Windows Defender with the release of Beta 2. Windows Defender is a freeware program designed to protect against spyware and other unwanted software. Windows XP and Windows Server 2003 users who have genuine copies of Microsoft Windows can freely download the program from Microsoft's web site, and Windows Defender ships as part of Windows Vista and 7.[40] In Windows 8, Windows Defender and Microsoft Security Essentials have been combined into a single program, named Windows Defender. It is based on Microsoft Security Essentials, borrowing its features and user interface. Although it is enabled by default, it can be turned off to use another anti-virus solution.[41] Windows Malicious Software Removal Tool and the optional Microsoft Safety Scanner are two other free security products offered by Microsoft.Third-party analysis
In an article based on a report by Symantec,[42] internetnews.com has described Microsoft Windows as having the "fewest number of patches and the shortest average patch development time of the five operating systems it monitored in the last six months of 2006."[43]A study conducted by Kevin Mitnick and marketing communications firm Avantgarde in 2004 found that an unprotected and unpatched Windows XP system with Service Pack 1 lasted only 4 minutes on the Internet before it was compromised, and an unprotected and also unpatched Windows Server 2003 system was compromised after being connected to the internet for 8 hours.[44] This study does not apply to Windows XP systems running the Service Pack 2 update (released in late 2004), which vastly improved the security of Windows XP.[citation needed] The computer that was running Windows XP Service Pack 2 was not compromised. The AOL National Cyber Security Alliance Online Safety Study of October 2004 determined that 80% of Windows users were infected by at least one spyware/adware product.[citation needed] Much documentation is available describing how to increase the security of Microsoft Windows products. Typical suggestions include deploying Microsoft Windows behind a hardware or software firewall, running anti-virus and anti-spyware software, and installing patches as they become available through Windows Update.[45]
Emulation software
Emulation allows the use of some Windows applications without using Microsoft Windows. These include:- Wine – a free and open source software implementation of the Windows API, allowing one to run many Windows applications on x86-based platforms, including UNIX/Linux and OS X. Wine developers refer to it as a "compatibility layer";[46] and make use of Windows-style APIs to emulate the Windows environment.
- CrossOver – A Wine package with licensed fonts. Its developers are regular contributors to Wine, and focus on Wine running officially supported applications.
- Cedega – TransGaming Technologies' proprietary fork of Wine, designed specifically for running games written for Microsoft Windows under Linux. A version of Cedega known as Cider is used by some video game publishers to allow Windows games to run on OS X. Since Wine was licensed under the LGPL, Cedega has been unable to port the improvements made to Wine to their proprietary codebase. Cedega ceased its service in February 2011.
- Darwine – A bundling of Wine to the PowerPC Macs running OS X by running Wine on top of QEMU. Intel Macs use the same Wine as other *NIX x86 systems.
- ReactOS – An open-source OS that is intended to run the same software as Windows, originally designed to simulate Windows NT 4.0, now aiming at Windows XP and Vista/7 compatibility. It has been in the development stage since 1996.
- Freedows OS – an open source attempt at creating a Windows clone for x86 platforms, intended to be released under the GNU General Public License. Started in 1996 by Reece K. Sellin, the project was never completed, getting only to the stage of design discussions which featured a number of novel concepts until it was suspended in 2002.[47][48][49]
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