Microsoft Windows is a group of several graphical operating system families, all of which are developed, marketed, and sold by Microsoft. Each family caters to a certain sector of the computing industry. Active Windows families include Windows NT and Windows Embedded; these may encompass subfamilies, e.g. Windows Embedded Compact (Windows CE) or Windows Server. Defunct Windows families include Windows 9x, Windows Mobile and Windows Phone.

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 (GUIs).[1] Microsoft Windows came to dominate the world's personal computer (PC) market with over 90% market share, overtaking Mac OS, which had been introduced in 1984. Apple came to see Windows as an unfair encroachment on their innovation in GUI development as implemented on products such as the Lisa and Macintosh (eventually settled in court in Microsoft's favor in 1993). On PCs, Windows is still the most popular operating system. However, in 2014, Microsoft admitted losing the majority of the overall operating system market to Android,[2] because of the massive growth in sales of Android smartphones. In 2014, the number of Windows devices sold was less than 25% that of Android devices sold. This comparison however may not be fully relevant, as the two operating systems traditionally target different platforms. Still, numbers for server use of Windows (that are comparable to competitors) show one third market share, similar to for end-user use.

As of April 2021, the most recent version of Windows for PCs, tablets, smartphones and embedded devices is Windows 10. The most recent versions for server computers is Windows Server 2019. A specialized version of Windows runs on the Xbox One video game console.[3] Microsoft is scheduled to announce Windows 11 on June 24, 2021.[4][5]


There have been many versions of Windows since its introduction in 1985, ranging from 16-bit to 64-bit, for both client and server applications.

All versions based on the consumer operating system (that has been released)

All versions based on the server an businesses operating system (that has been released)


Windows was first originated as an add-on to MS-DOS to provide a graphical user interface to the traditional command-line system.

Windows 1.0

A typical Windows 1.0 desktop.

The first independent version of Microsoft Windows, version 1.0, released in November 1985, lacked a degree of functionality and achieved little popularity.

Windows 2.0

Windows 2.0 was released in November 1987 and was slightly more popular than its predecessor. Windows 2.03 (release date January 1988) had introduced overlapping windows, which led to Apple Computer filing a suit against Microsoft alleging copyright infringement.

Windows 3.0

A typical Windows 3.11 Workgroup desktop.

Windows 3.0, released in 1990, was the first Windows version to achieve broad commercial success, selling 2 million copies in the first six months. It featured improvements to the user interface and to multitasking capabilities. It was updated to version 3.1 in 1992.

Windows NT 3.1

In July 1993, Microsoft released Windows NT based on IBM OS/2 technology (which Microsoft had been co-developing for several years prior). NT was targeted at businesses rather than home users, although these separate lines would later be combined.

Windows 95

In August 1995, Microsoft released Windows 95, which introduced the Start Menu which is still in use 15 years later.

Windows 98

The next in line was Microsoft Windows 98 released in June 1998. Substantially criticized for its slowness compared with Windows 95, many of its basic problems were later rectified with the release of Windows 98 Second Edition in 1999.

Windows 2000/Me

As part of its business line, Microsoft released the NT-based Windows 2000 in February 2000, which was used for servers and workstations alike. The consumer version was the 9x-based Windows Me (Millennium Edition), released in September 2000. Windows Me attempted to implement a number of new technologies for Microsoft, most notably Universal Plug and Play, however, the OS was substantially criticized for its lack of compatibility and stability.

Windows XP

In October 2001, Microsoft released Windows XP, a version built on the Windows NT kernel that also retained the consumer-oriented usability of Windows 95 and its successors. It 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 "Media Center" edition was released in 2003, with an emphasis on support for DVD and TV functionality including program recording and a remote control.

Windows Server 2003

Windows Server 2003 was introduced in April 2003, 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 (Release 2).

Windows Vista

The long-awaited Windows Vista, codenamed Longhorn, was released in 2007 with 5 editions. Vista was built on the more recent and more stable platform of Server 2003. Windows Server 2008 was introduced in February 2008.

Windows 7

In October 2009, Windows 7 was launched as the successor to Vista, and is considered to be a lot more stable and usable than its predecessor. At the same time, Windows Server 2008 R2 was launched as an update to the server line.

Windows 8

In October 26, 2012, Windows 8 was launched as the successor to Windows 7 and introduced major changes to the OS's platform and user interface to improve experience on mobile devices, because Windows was now competing with mobile OS's. Windows Server 2012 was also released.

Windows 8.1

Windows 8.1 was released on October 17, 2013 to address complaints of Windows 8. It included visual enhancements, new apps, and support for new technologies. It received more acceptance than Windows 8. Windows Server 2012 R2 was released at that time.

Windows 10

Windows 10 came out July 29, 2015 as the successor to Windows 8.1. Windows 10 has support for universal apps. The user interface was designed to handle changes between a mouse-based interface and a touchscreen interface and other new changes were made. Windows Server 2016 and Windows Server 2019 were added during its time. Windows 10 was said to be the last Windows OS, receiving bi-annual updates usually around March and October of each year. The latest build is 2004.

Windows 11

Windows 11 was leaked on June 15, 2021 and is scheduled to be formally announced on June 24.[4][5]


A typical Windows XP desktop.

The most obvious feature of Windows is a window or a container for other graphical objects. A Window in Microsoft Windows typically contains a status bar, title bar, minimize and maximize buttons, close button, and system menu (also called the windows menu or control menu). Another prominent feature since Windows 95 and NT 4.0 is the desktop, which holds various icons that the user can double-click to open. The Start Button and Start Menu, attached to the taskbar and typically below the desktop, gives users access to installed programs and many of the other features of the operating system.

Due to these and features, Windows makes it possible to perform most common tasks, some quite complex, with very little computer knowledge. Windows also comes with features to help the disabled through its accessibility options. Under Windows XP, these features include the Narrator, Magnifier, and contrast display mode.

Logo timeline

1985-2001 as Microsoft Windows 1.0x-2.x

Windows logo (1985-2001).png

1988-2001 as Microsoft Windows 3.0


1991-2010 as Microsoft Windows 3.1-2000

1992-2000 Windows logo.png

1995-2006 as Microsoft Windows 9x

1995-2000 and 2005 Windows logo.png

2001-2014 as Windows XP

2001-2011 Windows logo.png

2006-2012 as Windows Vista-7

Windows logo - 2006.svg.png

2012-2015 as Windows 8


2015-2021 as Windows 10

Windows 10 Logo.png

2021-present as Windows 11

Windows 11 logo build 21996.1.svg

Widespread usage

Microsoft Windows is installed on the vast majority of personal computers. A July 2005 poll of Network Computing magazine readers found that 90% of their organizations used Microsoft's desktop operating systems. It has achieved enormous market penetration due to the domination of MS-DOS in the early days of PC compatible computers (IBM PC clones). It is also the primary platform for Microsoft Office and most non-console computer games.

The widespread use of Microsoft's operating system has benefited from not being tied to the success of one hardware manufacturer and from Microsoft's willingness to license the operating system to manufacturers. This is in contrast with Apple Computer, which does not license Mac OS X to other manufacturers, and Sun Microsystems, which did not license Solaris before it was made free and open-source. However, the wide spectrum of possible hardware permutations with Microsoft Windows is also a major source of computer problems because of hardware-software incompatibilities for consumers.

In the past, companies who wanted to be in the computer business had to create their own operating systems (such as the Amiga, BBC Micro or ZX Spectrum) or choose another OS; even an exclusive license with one vendor was significantly cheaper than developing and supporting a new operating system and software base.

Due to Microsoft's extensive licensing agreements with many computer vendors, Windows presently comes pre-installed on most computers as a bundled OEM version, making it the default or only choice for most of the market.

For some consumers, Windows is the only valid option for a computing environment, or it is mandated by their workplace; additionally, an unfamiliarity with other operating systems results in a lack of desire to switch to other operating systems. A significant percentage of computer users simply lack the technical knowledge needed to install an operating system.

Finally, the large base of software available exclusively for the Windows family of operating systems has become the single largest self-perpetuating reason for the popularity of Windows. In recent years, many companies have been started with the sole intention of releasing Windows software; the fact that there is already a large customer base in place is reason enough for such companies to spend their resources solely on Windows software development. As a result, the fact that many companies are supporting Windows exclusively is a self-reinforcing reason for customers to choose Windows.

Maintaining compatibility in a new release of Windows with this large collection of software designed to run on older flavors of Windows consumes a large part of the resources of the Windows development team.


The Windows XP Security Center supplied in Service Pack 2.

Security has been a major weakness of Windows for many years, and even Microsoft itself has been the victim of cracks and hacks. Due to the widespread usage of Windows on personal computers, many crackers (also known as black hat hackers) have targeted Windows rather than the lesser-used operating systems such as Linux, Unix, Mac OS X, and FreeBSD. Some believe that due to being designed for security in a multi-user and/or networked environment some other operating systems have a relatively small number of security issues. Windows was 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. Combined with occasionally flawed code (such as buffer overflows), Windows is a continuous target of worms and virus writers. Furthermore, until Service Pack 2 of Windows XP most versions of Windows were shipped with important security features disabled by default, and vulnerable albeit useful system services enabled by default. 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.

Microsoft publicly admitted their ongoing security problems shortly after the turn of the century and now claims to regard security as their number one priority. As a result, Service Pack 2 for Windows XP greatly increased the security of the operating system. 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. In Windows 2000 (Service Pack 3 and later), Windows Me, and Windows XP, updates can be automatically downloaded and installed if the user selects to do so.

As another step in their focus on security, Microsoft has released Windows Defender (formerly Windows AntiSpyware and Giant AntiSpyware) a free program designed to protect against spyware and other unwanted software.

A study conducted by Kevin Mitnick and marketing communications firm Avantgarde found that an unprotected and unpatched Windows XP system lasted only 4 minutes on the Internet before it was 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. 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.

See also


  1. "The Unusual History of Microsoft Windows". Retrieved April 22, 2007. 
  2. Keizer, Gregg (July 14, 2014). "Microsoft gets real, admits its device share is just 14%". IDG. Archived from the original on August 21, 2016. "[Microsoft's chief operating officer] Turner's 14% came from a new forecast released last week by Gartner, which estimated Windows' share of the shipped device market last year was 14%, and would decrease slightly to 13.7% in 2014. [..] Android will dominate, Gartner said, with a 48% share this year" 
  3. cite web|url= One Architecture Finally Explained - Runs OS 'Virtually Indistinguishable' from Windows 8|work=WCCFtech|deadurl=no|archiveurl= 6, 2015|df=mdy-all}}
  4. 4.0 4.1 Microsoft to unveil new version of Windows on June 24, by Jordan Novet, CNBC. 2021-06-02.
  5. 5.0 5.1 Windows 11 with new UX confirmed in a leak, ahead of Microsoft's June 24 announcement by Zac Bowden and Daniel Rubino, Windows Central. 2021-06-15.

External links


Tips and documentation

Programming Microsoft Windows


  • RSWL – free Reliable Software C++ Windows API library.

Reviews and evaluation


Microsoft Windows family
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Windows Server
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Windows EmbeddedWindows PEWindows Fundamentals for Legacy PCs
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