Windows 1.0

Windows 1.0 is a 16-bit graphical operating environment released on November 20, 1985. It was Microsoft's first attempt to implement a multi-tasking graphical user interface-based operating environment on the PC platform.Windows 1.0 offers limited multitasking of existing MS-DOS programs and concentrates on creating an interaction paradigm (cf. message loop), an execution model and a stable API for native programs for the future. Due to Microsoft's extensive support for backward compatibility, it is not only possible to execute Windows 1.0 binary programs on current versions of Windows to a large extent, but also to recompile their source code into an equally functional "modern" application with just limited modifications.[citation needed].
Windows 1.0 is often regarded as a "front-end to the MS-DOS operating system", a description which has also been applied to subsequent versions of Windows. Windows 1.0 is an MS-DOS program. Windows 1.0 programs can call MS-DOS functions, and GUI programs are run from .exe files just like MS-DOS programs. However, Windows .exe files had their own "new executable" (NE) file format, which only Windows could process and which, for example, allowed demand-loading of code and data. Applications were supposed to handle memory only through Windows' own memory management system, which implemented a software-based virtual memory scheme allowing for applications larger than available RAM.
Because graphics support in MS-DOS is extremely limited, MS-DOS applications have to go to the bare hardware (or sometimes just to the BIOS) to get work done. Therefore, Windows 1.0 included original device drivers for video cards, a mouse, keyboards, printers and serial communications, and applications were supposed to only invoke APIs built upon these drivers. However, this extended to other APIs such as file system management functions. In this sense, Windows 1.0 was designed to be extended into a full-fledged operating system, rather than being just a graphics environment used by applications. Indeed, Windows 1.0 is a "DOS front-end" and cannot operate without a DOS environment (it uses, for example, the file-handling functions provided by DOS.) The level of replacement increases in subsequent versions.

Windows 3.0

Windows 3.0 is the third major release of Microsoft Windows, and came out on May 22, 1990. It became the first widely successful version of Windows (see history of Microsoft Windows) and a powerful rival to Apple Macintosh and the Commodore Amiga on the GUI front. It was succeeded by Windows 3.1.Windows 3.0 succeeded Windows 2.1x and included a significantly revamped user interface as well as technical improvements to make better use of the memory management capabilities of Intel's 80286 and 80386 processors. Text-mode programs written for MS-DOS could be run within a window (a feature previously available in a more limited form with Windows/386 2.1), making the system usable as a crude multitasking base for legacy programs. However, this was of limited use for the home market, where most games and entertainment programs continued to require raw DOS access.
The MS-DOS Executive file manager/program launcher was replaced with an icon-based Program Manager and a list-based File Manager, thereby simplifying the launching of applications. The MS-DOS Executive is also included as an alternative to these. The Control Panel, previously available as a standard-looking applet, was re-modeled after the one in Mac OS. It centralized system settings, including limited control over the color scheme of the interface. A number of simple applications were included, such as the text editor Notepad and the word processor Write (both inherited from earlier versions of Windows), a macro recorder (new; later dropped), and a calculator (also inherited). The earlier Reversi game was complemented with a card game named Solitaire.
Windows 3.0 was the last version of Windows to advertise 100% compatibility with older Windows applications

Windows 3.1x

Windows 3.1x is a graphical user interface and a part of the Microsoft Windows software family. Several editions were released between 1992 and 1994, succeeding Windows 3.0. This family of Windows can run in either Standard or 386 Enhanced memory modes. The exception is Windows for Workgroups 3.11, which can only officially run in 386 Enhanced mode.

Windows NT 3.51

Windows NT 3.51 is the third release of Microsoft's Windows NT line of operating systems. It was released on May 30, 1995, nine months after Windows NT 3.5. The release provided two notable feature improvements; firstly NT 3.51 was the first of a short-lived outing of Microsoft Windows on the PowerPC CPU architecture. The second most significant enhancement offered through the release was that it provides client/server support for interoperating with Windows 95, which was released three months after NT 3.51. Windows NT 4.0 became its successor a year later; Microsoft continued to support 3.51 until December 31, 2001.

Windows 95

Windows 95 is a consumer-oriented graphical user interface-based operating system. It was released on August 24, 1995 by Microsoft, and was a significant progression from the company's previous Windows products. During development it was referred to as Windows 4.0 or by the internal codename Chicago.
Windows 95 was intended to integrate Microsoft's formerly separate MS-DOS and Windows products and includes an enhanced version of DOS, often referred to as MS-DOS 7.0. It features significant improvements over its predecessor, Windows 3.1, most visibly the graphical user interface (GUI) whose basic format and structure is still used in later versions such as Windows Vista. There were also large changes made to the underlying workings, including support for 255-character mixed-case long filenames and preemptively multitasked protected-mode 32-bit applications. Whereas its predecessors are optional "operating environments" requiring the MS-DOS operating system (usually available separately), Windows 95 is a consolidated operating system, which was a significant marketing change.

MS DOS

MS-DOS (short for Microsoft Disk Operating System) is an operating system commercialised by Microsoft. It was the most commonly used member of the DOS family of operating systems and was the dominant operating system for the PC compatible platform during the 1980s. It has gradually been replaced on consumer desktop computers by various generations of the Windows operating system.MS-DOS was originally released in 1981 and had eight major versions released before Microsoft stopped development in 2000. It was the key product in Microsoft's growth from a programming languages company to a diverse software development firm, providing the company with essential revenue and marketing resources. It also provided the platform on which early versions of Windows ran.

Windows 2.0

Windows 2.0 allowed application windows to overlap each other, unlike its predecessor Windows 1.0, which could only display tiled windows. Windows 2.0 also introduced more sophisticated keyboard-shortcuts and the terminology of "Minimize" and "Maximize", as opposed to "Iconize" and "Zoom" in Windows 1.0.The first Windows versions of Microsoft Word and Microsoft Excel ran on Windows 2.0. Third-party developer support for Windows increased substantially with this version (some shipped the Windows Runtime software with their applications, for customers who had not purchased the full version of Windows). However, most developers still maintained DOS versions of their applications, as Windows users were still a distinct minority of their market.

Windows 98

Windows 98 Second Edition (often shortened to SE) is an update to Windows 98, released on May 5, 1999. It includes fixes for many minor issues, improved USB support, and the replacement of Internet Explorer 4.0 with the significantly faster Internet Explorer 5. Also included is Internet Connection Sharing, which allow multiple computers on a LAN to share a single Internet connection through Network Address Translation. Other features in the update include Microsoft NetMeeting 3.0 and integrated support for DVD-ROM drives. However, it is not a free upgrade for Windows 98, but a stand-alone product. This can cause problems if programs specifically request Windows 98 SE, but the user only owns Windows 98. Also included on the CD-ROM is the option to install Microsoft Plus! themes for Windows 98.Windows 98 was the first operating system to use the Windows Driver Model (WDM). This fact was not well published when Windows 98 was released and most hardware producers continued to develop drivers for the older driver standard, VxD. This resulted in the misconception that Windows 98 can use only VxD drivers. The WDM standard spread years after its release, mostly through Windows 2000 and Windows XP, because these systems are not compatible with the older VxD standard. Today, even if hardware producers are not developing drivers optimized for Windows 98, the drivers written to WDM standards are compatible with Windows 98–based systems.

Windows 2000

Windows 2000 (also referred to as Win2K) is a preemptive, interruptible, graphical and business-oriented operating system designed to work with either uniprocessor or symmetric multi-processor computers. It is part of the Microsoft Windows NT line of operating systems and was released on February 17, 2000. It was succeeded by Windows XP in October 2001 and Windows Server 2003 in April 2003. Windows 2000 is classified as a hybrid kernel operating system.Windows 2000 was made available in four editions: Professional, Server, Advanced Server, and Datacenter Server. Additionally, Microsoft offered Windows 2000 Advanced Server Limited Edition and Windows 2000 Datacenter Server Limited Edition, which were released in 2001 and run on 64-bit Intel Itanium microprocessors.[4] Whilst all editions of Windows 2000 are targeted to different markets, they each share a core set of common functionality, including many system utilities such as the Microsoft Management Console and standard system administration applications. Support for people with disabilities was improved over Windows NT 4.0 with a number of new assistive technologies, and Microsoft included increased support for different languages and locale information. All versions of the operating system support the Windows NT filesystem, NTFS 3.0,[5] the Encrypting File System, as well as basic and dynamic disk storage. The Windows 2000 Server family has additional functionality, including the ability to provide Active Directory services (a hierarchical framework of resources), Distributed File System (a file system that supports sharing of files) and fault-redundant storage volumes. Windows 2000 can be installed and deployed to corporate desktops through either an attended or unattended installation. Unattended installations rely on the use of answer files to fill in installation information, and can be performed through a bootable CD using Microsoft Systems Management Server, by the System Preparation Tool. Windows 2000 is the last NT-kernel based version of Microsoft Windows that does not include Windows Product Activation.At the time of its release, Microsoft marketed Windows 2000 as the most secure Windows version they had ever shipped,[6] however it became the target of a number of high-profile virus attacks such as Code Red and Nimda. More than seven years after its release, it continues to receive patches for security vulnerabilities on a near-monthly basis.

Windows XP

Windows XP is a line of operating systems developed by Microsoft for use on general-purpose computer systems, including home and business desktops, notebook computers, and media centers. The letters "XP" stand for eXPerience.[2] It was codenamed "Whistler", after Whistler, British Columbia, as many Microsoft employees skied at the Whistler-Blackcomb ski resort during its development. Windows XP is the successor to both Windows 2000 Professional and Windows Me, and is the first consumer-oriented operating system produced by Microsoft to be built on the Windows NT kernel and architecture. Windows XP was first released on October 25, 2001, and over 400 million copies were in use in January 2006, according to an estimate in that month by an IDC analyst.[3] It is succeeded by Windows Vista, which was released to volume license customers on November 8, 2006, and worldwide to the general public on January 30, 2007.The most common editions of the operating system are Windows XP Home Edition, which is targeted at home users, and Windows XP Professional, which has additional features such as support for Windows Server domains and two physical processors, and is targeted at power users and business clients. Windows XP Media Center Edition has additional multimedia features enhancing the ability to record and watch TV shows, view DVD movies, and listen to music. Windows XP Tablet PC Edition is designed to run the ink-aware Tablet PC platform. Two separate 64-bit versions of Windows XP were also released, Windows XP 64-bit Edition for IA-64 (Itanium) processors and Windows XP Professional x64 Edition for x86-64.Windows XP is known for its improved stability and efficiency over the 9x versions of Microsoft Windows. It presents a significantly redesigned graphical user interface, a change Microsoft promoted as more user-friendly than previous versions of Windows. New software management capabilities were introduced to avoid the "DLL hell" that plagued older consumer-oriented 9x versions of Windows. It is also the first version of Windows to use product activation to combat software piracy, a restriction that did not sit well with some users and privacy advocates. Windows XP has also been criticized by some users for security vulnerabilities, tight integration of applications such as Internet Explorer and Windows Media Player, and for aspects of its default user interface.

Windows Vista

Windows Vista (IPA: /ˈvɪs.tə/) is a line of graphical operating systems used on personal computers, including home and business desktops, laptops, Tablet PCs, and media centers. Prior to its announcement on July 22, 2005, Windows Vista was known by its codename "Longhorn".[1] Development was completed on November 8, 2006; over the following three months it was released in stages to computer hardware and software manufacturers, business customers, and retail channels. On January 30, 2007, it was released worldwide to the general public,[2] and was made available for purchase and downloading from Microsoft's web site.[3] The release of Windows Vista comes more than five years after the introduction of its predecessor, Windows XP, making it the longest time span between two releases of Microsoft Windows.