Microsoft Windows

Microsoft Windows

Windows logo Windows logo File:Default xp theme.JPG A screenshot of Microsoft Windows XP Professional
Developer	Microsoft Corporation
OS family	MS-DOS-based, Windows NT, Windows CE
Working state	Current
Source model	Mostly closed source
Latest release	24H2 (10.0.26100.3915) (April 25, 2025 (2025-04-25)) [±]
Latest preview	Release Preview Channel 24H2 (10.0.26100.3915) (April 25, 2025 (2025-04-25)) [±] Beta Channel 24H2 (10.0.26120.3950) (May 5, 2025 (2025-05-05)) [±] Dev Channel 24H2 (10.0.26200.5581) (May 5, 2025 (2025-05-05)) [±] Canary Channel 10.0.27842.1000 (April 23, 2025 (2025-04-23)) [±] .
Kernel type	Hybrid
License	Microsoft EULA
Official website	[1]

Microsoft Windows is a range of operating environments and operating systems for personal computers and servers. The range was first introduced by Microsoft in 1985 as an add-on to MS-DOS to counter Apple's new system, the Apple Macintosh, which used a graphical user interface (GUI). Microsoft Windows eventually came to dominate the world personal computer market with market analysts like IDC estimating that Windows has around 90% of the client operating system market. [2] All recent versions of Windows are fully-fledged operating systems. Windows is proprietary closed source software: Microsoft Corporation owns the software's copyright and controls its distribution.

Windows was developed for IBM PC-compatible computers (these were based on Intel x86 architecture), and today, almost all versions of Windows are made for this hardware-platform (although Windows NT was written as a cross-platform system for Intel and MIPS processors, and later appeared on the PowerPC and DEC Alpha architectures). The popularity of Windows made Intel CPUs more popular and vice versa. In fact, the term Wintel became used to describe PC-compatible computers running a version of Windows.

Microsoft Windows versions

The term Windows is used as a collective term for several generations of operating system products which can be classified into the following categories:

16-bit operating environments. The early versions of Windows were just graphical user interfaces or desktops, mostly because they used the underlying MS-DOS for file system services and all operating processes. Soon, 16-bit Windows versions would have their own executable file format and provide their own device drivers (graphics, printer, mouse, keyboard and sound). Unlike DOS, the Windows environment allowed all users to execute multiple graphical applications at the same time (cooperative multitasking). Finally, they implemented a software segment-based virtual memory scheme which allowed the GUI to run applications larger than available memory: code segments and resources are swapped in and thrown away when useless or memory becomes scarce and data segments move in memory when a given application has relinquished processor control. Examples include Windows 1.0 (1985) and Windows 2.0 (1987) and its close relative Windows/286.

Hybrid 16/32-bit operating environments. Windows/386 introduced a 32-bit protected mode kernel and virtual machine monitor. For the duration of a Windows session, it provided a device virtualization for the disk controller, video card, keyboard, mouse, timer and interrupt controller. The user-visible consequence was that it became possible to preemptively multitask multiple MS-DOS environments in separate windows (graphical applications required switching the window to full screen mode). Windows applications were still multi-tasked cooperatively inside a real-mode environment. Windows 3.0 (1990) and Windows 3.1 (1992) perfected the design, notably thanks to virtual memory and loadable virtual device drivers (VxDs) which allowed them to share arbitrary devices between multitasked DOS windows. Most important, Windows applications could now run in 16-bit protected mode (when Windows was running in Standard or 386 Enhanced Mode), which gave them access to several megabytes of memory and removed the obligation to participate in the software virtual memory scheme. They still ran inside the same address space, where the segmented memory provided a degree of protection, and multi-tasked cooperatively. For Windows 3.0 Microsoft also rewrote critical operations from C into assembly, making this release faster and less memory-hungry than its predecessors.

Hybrid 16/32-bit operating system. With the introduction of 32-Bit File Access in Windows for Workgroups 3.11, Windows could finally stop relying on DOS for file management. Leveraging this, Windows 95 introduced Long File Names, reducing the 8.3 DOS to the role of a boot loader. MS-DOS was now bundled with Windows; this notably made it (partially) aware of long file names when its utilities were run from within Windows, but angered the competition. The most important novelty was the possibility of running 32-bit multi-threaded preemptively multitasked graphical programs. There were three releases of Windows 95 (the first in 1995, then subsequent bug-fix versions in 1996 and 1997, only released to OEMs, which added extra features such as FAT32 support). Microsoft's next OS was Windows 98; there were two versions of this (the first in 1998 and the second, named "Windows 98 Second Edition", in 1999). In 2000, Microsoft released Windows Me (Me standing for Millennium Edition), which used the same core as Windows 98 but adopted the visual appearance of Windows 2000, as well as a new feature called System Restore, allowing the user to set the computer's settings back to an earlier date. It was not a very well received implementation, and many user problems occurred. ME was considered a stopgap to the day both product lines would be seamlessly merged. Microsoft left little time for Windows Me to become popular before announcing their next version of Windows which would be called XP.

32-bit operating systems originally designed and marketed for higher-reliability business use with no DOS heritage. The first release was Windows NT 3.1 (1993, numbered "3.1" to match the Windows version and to one-up OS/2 2.1, IBM's flagship OS codeveloped by Microsoft and Windows NT's main competitor at the time), which was followed by NT 3.5 (1994), NT 3.51 (1995), and NT 4.0 (1996); the latter implemented the Windows 95 user interface. Microsoft then moved to combine their consumer and business operating systems. Their first attempt, Windows 2000, failed to meet their goals, and was released as a business system. The home consumer edition of Windows 2000, codenamed "Windows Neptune", ceased development and Microsoft released Windows Me in its place. Eventually "Neptune" was merged into their new project, Whistler, which later became Windows XP. Since then, a new business system, Windows Server 2003, has expanded the top end of the range, and the forthcoming Windows Vista will complete it. Windows CE, Microsoft's offering in the mobile and embedded markets, is also a true 32-bit operating system.

64-bit operating systems, the newest category, are designed for AMD's AMD64 CPU architecture, Intel's Intel Architecture 64-bit, and EM64T. The 64-bit Windows family comprises Windows XP Itanium edition, Professional x64 Edition, and Windows Server 2003; Windows XP Professional and Server 2003 x64 editions were released on April 25, 2005. Itanium editions already came out in 2002. Early indications are that Windows Vista, the projected successor to Windows XP, will be released in both 32-bit and 64-bit versions.

See also: List of Microsoft Windows versions.

Microsoft Windows history

Main article: History of Microsoft Windows

The first independent version of Microsoft Windows, version 1.0, released in 1985, lacked a degree of functionality and achieved little popularity. Windows 1.0 did not provide a complete operating system; rather, it extended MS-DOS. Microsoft Windows version 2.0 was released in 1987 and was slightly more popular than its predecessor.

Microsoft Windows version 3.0, released in 1990, was the first version to achieve broad commercial success. It featured improvements to the user interface and to multitasking capabilities. In 1995, Microsoft released Windows 95, which made further changes to the user interface.

In 2001, Microsoft released Windows XP, a version that used the kernel from Microsoft Windows NT. With Windows XP, Microsoft merged the consumer-oriented Windows 3.1 line with the more commercially-oriented Windows NT line of products.

Interface

File:Windows xp desktop.PNG

A typical Windows XP desktop.

The most obvious feature of the more recent Windows versions (since Windows 95 and NT 4.0) besides the window, is the desktop, which holds various icons, or graphical objects that the user can double-click to open. Windows has produced a significant change in the way people interact with computers; it is possible to perform most common tasks, some quite complex, with very little computer knowledge.

Another quite significant feature of Windows since Windows 95 is the Start Button and Start Menu, which gives users access to installed programs and many of the other features of the operating system. It is attached to the taskbar (blue in the picture on the right).

Windows XP introduced a new visual style dubbed "Luna", which updated the classic Windows style (a plain grey box look) with a more graphical appearance. The new style features bold colors and a larger titlebar and start button, which some people have labelled immature or childish. Users can still elect to use the old Windows 9x/2000 visual style.

There is a view that modern operating systems need to cater to the vastly increased user base with a lower average computer skill level and the increased power and complexity of modern computer systems.

However, some users accuse the Windows interface of isolating the user from too much of the inner workings of the computer, making it more difficult to control, configure and troubleshoot some system features.

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. However, these are not suitable for everyone. Other customized builds of other operating systems may provide the needed features.

Popularity

Microsoft Windows is installed on the majority of personal computers. A July 2005 poll of Network Computing magazine readers found that 87% of their organisations used Microsoft's desktop operating systems. [3] It 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 many computer games.

Microsoft's operating system has also benefited from not being tied to the success of one hardware manufacturer, and from Microsoft's willingness to license the operating system to manufacturers. For example, this is in contrast with Apple Computer, which does not license Mac OS X to other manufacturers, as well as Sun, which did not license Solaris before it was made free and open-source.

In the past, companies who wanted to be in the computer business had to create their own operating system (such as the Amiga) 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 exclusive licensing agreements with many computer vendors, Windows today comes pre-installed on most computers as a bundled OEM version, making it the default or only choice for much of the market. Most consumers do not delete Windows and install another operating system.

For some consumers, Windows is the only valid option as their computing environment or is mandated by their workplace; additionally, the unfamiliarity with most other operating systems limits the desire to switch to other operating systems. Further, a growing part of the computer market lacks the technical knowledge needed to install an operating system.

Finally, the large software base of programs available 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 started up 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 only spend resources on Windows software development. In turn, the fact that many companies are supporting Windows exclusively is reason for many customers to choose Windows.

Security

Windows XP Security Center

Security has been a major weakness of Windows for many years. Due to the widespread usage of Windows on desktops, 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. Additionally most modern operating systems were designed for security in a multi-user and/or networked environment and 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 continous target of worms 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.

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 increases the security. Microsoft releases security patches through its Windows Update service approximately once a month, although critical updates are made available at shorter intervals. In Windows 2000 and Windows XP, updates can be automatically downloaded and installed if the user elects to do so.

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. [4] 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. [5] Much documentation is available describing how to increase the security of Microsoft Windows products. Typical suggestions include deploying Microsoft Windows behind a hardware firewall, running anti-virus and anti-spyware software, and installing patches as they become available through Windows Update.

Windows emulation software

Emulation allows the use of some Windows applications without using Microsoft Windows. These include:

• WINE – an almost complete free software / open source software implementation of the Windows API, allowing one to run some Windows applications on x86 Unix-based platforms, including Linux.
• Cedega (formerly known as WineX) – TransGaming Technologies' proprietary fork of WINE, which is designed specifically for running games written for Microsoft Windows under Linux.
• ReactOS – open source operating system, aimed to be compatible with Windows NT apps and drivers.
• Freedows and Alliance OS – a very ambitious project, and a subsequent spinoff, that tried to clone Windows but withered away.
• Project David – ambitious and controversial project to fully emulate Windows programs to run on other OSs.
• CrossOver Office – another WINE spin-off that allows Windows programs to run on other OSs.
• Captive NTFS – a software "wrapper" for fuller, more-compatible open-source implementations of the Windows NTFS file system.
• ndiswrapper – a driver wrapper designed to let Linux/IA32 use Windows drivers for wireless networking hardware.
• E/OS – a virtual machine emulation system that strives for making it possible to run any program designed for any operating system without the need to actually install any other operating system.

See also

• Architecture of Windows 2000
• Blue Screen of Death
• Comparison of operating systems
• Hardware
  • Hardware abstraction layer
  • KMixer
  • VGASAVE
  • Windows Driver Model
  • WinHEC
• History of Microsoft Windows
• List of operating systems
• Microsoft Anti-Virus for Windows
• Microsoft Visual Studio
• Volume Shadow Copy Service
• Windows Blackcomb – next generation server platform
• Windows Explorer
• Windows Genuine Advantage
• Windows Media
• Windows vs. Linux

External links

Official

• Microsoft's Official Windows Website
• Official Promotional Website (Windows.com)
• Windows history time line from Microsoft

Tips and documentation

• How to run multiple versions of Windows on one PC
• The Windows Documentation Project (wiki)
• "AeroXperience" – Windows Vista Information and Customization
• Securing Microsoft Windows (for Home and Small Business Users)
• Windows tips (security, stability, etc.) (wiki)
• Symantec Anti-Virus Research Center – excellent informational security resource, and Symantec are makers of Norton Anti-Virus (3rd party software sold separately)
• dotwhat? - File Extension Listing – a huge listing of file extensions and the programs that use them
• Windows – tips and tricks for Windows 98, ME, NT, 2000 and XP

Reviews and evaluation

• Paul Thurrott's SuperSite for Windows – an exhaustive evaluation of Microsoft's products and technologies
• "Time to Live on the Network" – a security study by Kevin Mitnick and AvantGarde (PDF)
• Windows XP: rough around the edges – an UI review of Windows XP
• Frank Mahler's Interface Hall Of Shame
• AOL/National Cyber Security Alliance Online Safety Study (October 2004) (PDF)
• Interface Hall of Shame – an analysis of user interfaces with a focus on Windows

Other

• Windows history – a Windows history time line graph by Éric Lévénez
• GUIdebook: Windows Gallery – a website dedicated to preserving and showcasing graphical user interfaces
• Download.com – application programs for download, for Windows operating systems
• Windows 20th Birthday