Windows NT in the context of Windows Vista

Windows CE, later known as Windows Embedded CE and Windows Embedded Compact, is a discontinued operating system developed by Microsoft for mobile and embedded devices. It was part of the Windows Embedded family and served as the software foundation of several products including the Handheld PC, Pocket PC, Auto PC, Windows Mobile, Windows Phone 7 and others.

Unlike Windows Embedded Standard, Windows For Embedded Systems, Windows Embedded Industry and Windows IoT, which are based on Windows NT, Windows CE uses a different kernel. Microsoft licensed it to original equipment manufacturers (OEMs), who could modify and create their own user interfaces and experiences, with Windows Embedded Compact providing the technical foundation to do so.

Windows 10 is a major release of Microsoft's Windows NT operating system. The successor to Windows 8.1, it was released to manufacturing on July 15, 2015, to retail on July 29, 2015, and was a free upgrade to users of Windows 7, 8, and 8.1. Its server counterparts are Windows Server 2016, 2019, and 2022. It was succeeded by Windows 11 in October 2021.

In contrast to the tablet-oriented approach of its predecessor, Windows 10 returned to a desktop-oriented interface in line with previous versions of Windows and reintroduced the Start menu. Other features included the Cortana virtual assistant, Task View and virtual desktops, Action Center, biometric authentication through Windows Hello, an improved Settings component, Xbox Live integration, and DirectX 12. Also, Microsoft Edge was introduced, deprecating Internet Explorer. Unlike previous NT releases, Windows 10 received free feature updates on an ongoing basis. Alternatively, enterprise environments can use long-term support milestones that receive only critical and security updates. An ARM version of Windows 10 was released in 2018.

In computing, an epoch is a fixed date and time used as a reference from which a computer measures system time. Most computer systems determine time as a number representing the seconds removed from a particular arbitrary date and time. For instance, Unix and POSIX measure time as the number of seconds that have passed since Thursday 1 January 1970 00:00:00 UT, a point in time known as the Unix epoch. The C# programming language and Windows NT systems up to and including Windows 11 and Windows Server 2022 measure time as the number of 100-nanosecond intervals that have passed since 00:00:00 UTC on 1 January in the years AD 1 and AD 1601, respectively, making those points in time the epochs for those systems.Computing epochs are almost always specified as midnight Universal Time on some particular date.

Windows 2000 is a major release of the Windows NT operating system developed by Microsoft, targeting the server and business markets. It is the direct successor to Windows NT 4.0, and was released to manufacturing on December 15, 1999, and then to retail on February 17, 2000 for all versions, with Windows 2000 Datacenter Server being released to retail on September 26, 2000.

Windows 2000 introduces NTFS 3.0, Encrypting File System, and basic and dynamic disk storage. Support for people with disabilities is improved over Windows NT 4.0 with a number of new assistive technologies, and Microsoft increased support for different languages and locale information. The Windows 2000 Server family has additional features, most notably the introduction of Active Directory, which in the years following became a widely used directory service in business environments. Although not present in the final release, support for Alpha (which was a 64-bit platform but only distributed as a 32-bit OS) was present in its alpha, beta, and release candidate versions. Its successor, Windows XP, only supports x86, x64 and Itanium processors. Windows 2000 was also the first NT release to drop the "NT" name from its product line.

OpenStep is an object-oriented application programming interface (API) specification developed by NeXT. It provides a framework for building graphical user interfaces (GUIs) and developing software applications. OpenStep was designed to be platform-independent, allowing developers to write code that could run on multiple operating systems, including NeXTSTEP, Windows NT, and various Unix-based systems. It has influenced the development of other GUI frameworks, such as Cocoa for macOS, and GNUstep.

OpenStep was principally developed by NeXT and Sun Microsystems, to allow advanced application development on Sun's operating systems, specifically Solaris. NeXT produced a version of OpenStep for its own Mach-based Unix OS, stylized in all capital letters as OPENSTEP. The software libraries that shipped with OPENSTEP are a superset of the original OpenStep specification, including many features from the original NeXTSTEP.

Windows Media Player (WMP, now officially referred to as Windows Media Player Legacy to distinguish it from the new Windows Media Player introduced with Windows 11) is the first media player and media library application that Microsoft developed to play audio and video on personal computers. It has been a component of the Microsoft Windows operating system, including Windows 9x, Windows NT, Pocket PC, and Windows Mobile. Microsoft also released editions of Windows Media Player for classic Mac OS, Mac OS X, and Solaris, but has since discontinued them.

In addition to being a media player, the app can rip audio file from compact discs, burn Audio CDs or MP3 CDs, synchronize content with a digital audio player or mobile devices, and stream media over the local network. Originally, it could connect to a number of digital music stores, allowing its users to purchase digital music. The default file formats are Windows Media Video (WMV), Windows Media Audio (WMA), and Advanced Systems Format (ASF), and its own XML based playlist format called Windows Playlist (WPL). The player is also able to utilize a digital rights management service in the form of Windows Media DRM.

Windows Server (formerly Windows NT Server) is a brand name for server-oriented releases of the Windows NT operating system (OS) that have been developed by Microsoft since 1993. The first release under this brand name is Windows NT 3.1 Advanced Server, an edition of Windows NT 3.1. With the release of Windows Server 2003, Microsoft started releasing new versions under the name Windows Server. The latest release of Windows NT under the Windows Server brand is Windows Server 2025.

Microsoft's history of developing operating systems for servers goes back to Windows NT 3.1 Advanced Server.

Windows Embedded Industry, formerly Windows Embedded POSReady and Windows Embedded for Point of Service (WEPOS), is an operating system developed by Microsoft as part of its Windows Embedded family of products. Based on Windows NT, Windows Embedded Industry is designed for use in industrial devices such as cash registers, automated teller machines, and self service checkouts.

Windows Embedded 8.1 Industry was the last release, with Windows IoT Enterprise superseding Windows Embedded Industry, Windows Embedded Standard, and Windows For Embedded Systems (FES).

Windows 8 is a major release of the Windows NT operating system developed by Microsoft. It was released to manufacturing on August 1, 2012, made available for download via MSDN and TechNet on August 15, 2012, and generally released for retail on October 26, 2012.

Windows 8 introduced major changes to the operating system's platform and user interface with the intention to improve its user experience on tablets, where Windows competed with mobile operating systems such as Android and iOS. In particular, these changes included a touch-optimized Windows shell and start screen based on Microsoft's Metro design language, integration with online services, the Windows Store, and a new keyboard shortcut for screenshots. Many of these features were adapted from Windows Phone, and the development of Windows 8 closely parallelled that of Windows Phone 8. Windows 8 also added support for USB 3.0, Advanced Format, near-field communication, and cloud computing, as well as a new lock screen with clock and notifications. Additional security features—including built-in antivirus software, integration with Microsoft SmartScreen phishing filtering, and support for Secure Boot on supported devices—were introduced. It was the first Windows version to support ARM architecture under the Windows RT branding. Single-core CPUs and CPUs without PAE, SSE2 and NX are unsupported in this version.

Windows 10 is a major release of the Windows NT operating system developed by Microsoft. Microsoft described Windows 10 as an "operating system as a service" that would receive ongoing updates to its features and functionality, augmented with the ability for enterprise environments to receive non-critical updates at a slower pace or use long-term support milestones that will only receive critical updates, such as security patches, over their five-year lifespan of mainstream support. It was released on 29 July 2015.

Windows 7 is a major release of the Windows NT operating system developed by Microsoft. It was released to manufacturing on July 22, 2009, and became generally available on October 22, 2009. It is the successor to Windows Vista, released nearly three years earlier. Windows 7's server counterpart, Windows Server 2008 R2, was released at the same time. It sold over 630 million copies before it was succeeded by Windows 8 in October 2012.

Extended support ended on January 14, 2020, over 10 years after the release of Windows 7; the operating system ceased receiving further updates after that date. A paid support program was available for enterprises, providing security updates for Windows 7 for up to three years since the official end of life.

Windows Phone (WP) is a discontinued mobile operating system developed by Microsoft for smartphones as the replacement successor to Windows Mobile and Zune. Windows Phone featured a new user interface derived from the Metro design language. Unlike Windows Mobile, it was primarily aimed at the consumer market rather than the enterprise market.

It was first launched in October 2010 with Windows Phone 7. Windows Phone 8 succeeded it in 2012, replacing the Windows CE-based kernel of Windows Phone 7 with the Windows NT kernel used by the PC versions of Windows (and, in particular, a large amount of internal components from Windows 8). Due to these changes, the OS was incompatible with all existing Windows Phone 7 devices, although it still supported apps originally developed for Windows Phone 7. In 2014, Microsoft released the Windows Phone 8.1 update, which introduced the Cortana virtual assistant, and Windows Runtime platform support to create cross-platform apps between Windows PCs and Windows Phone.

Windows 8.1 is a release of the Windows NT operating system based on Windows 8 developed by Microsoft. It was released to manufacturing on August 27, 2013, and broadly released for retail sale on October 17, 2013, about a year after the retail release of its predecessor, and succeeded by Windows 10 on July 29, 2015. Windows 8.1 was made available for download via MSDN and Technet and available as a free upgrade for retail copies of Windows 8 and Windows RT users via the Windows Store. A server version, Windows Server 2012 R2, was released on October 18, 2013.

Windows 8.1 aimed to address complaints of Windows 8 users and reviewers on launch. Enhancements include an improved Start screen, additional snap views, additional bundled apps, tighter OneDrive (formerly SkyDrive) integration, Internet Explorer 11 (IE11), a Bing-powered unified search system, restoration of a visible Start button on the taskbar, and the ability to restore the previous behavior of opening the user's desktop on login instead of the Start screen. Windows 8.1 also added support for then emerging technologies like high-resolution displays, 3D printing, Wi-Fi Direct, and Miracast streaming, as well as the ReFS file system.

Windows Server 2016 is the eleventh major version of the Windows NT operating system produced by Microsoft to be released under the Windows Server brand name. It was developed alongside Windows 10 and is the successor to the Windows 8.1-based Windows Server 2012 R2. The first early preview version (Technical Preview) became available on October 1, 2014 together with the first technical preview of System Center. Windows Server 2016 was released on September 26, 2016 at Microsoft's Ignite conference and reached general availability on October 12, 2016.

It was succeeded by Windows Server 2019 and the Windows Server Semi-Annual Channel, which was released in 2017. Mainstream support for Windows Server 2016 ended on January 11, 2022, and extended support will end on January 12, 2027.

Windows Server 2019 is the twelfth major version of the Windows NT operating system produced by Microsoft to be released under the Windows Server brand name. It is the second version of the server operating system based on the Windows 10 platform, after Windows Server 2016. It was announced on March 20, 2018 for the first Windows Insider preview release, and was released internationally on October 2, 2018, the same release date of Windows 10 version 1809. It was succeeded by Windows Server 2022 on August 18, 2021.

Mainstream support for Windows Server 2019 ended on January 9, 2024, and extended support will end on January 9, 2029.

Windows Server 2022 is the thirteenth major version of the Windows NT operating system produced by Microsoft to be released under the Windows Server brand name. It was announced at Microsoft's Ignite event from March 2–4, 2021. It was released on August 18, 2021, almost 3 years after Windows Server 2019, and a few months before the Windows 11 operating system.

Windows Server 2022 is based on the "Iron" codebase, unlike Windows 10 21H2, which is based on the "Vibranium" codebase like its predecessor 20H2; this renders the updates between Windows 10 21H2 and Windows Server 2022 incompatible. Like its predecessor, Windows Server 2019, it requires x64 processors.

Windows 11 is the current major release of Microsoft's Windows NT operating system, released on October 5, 2021, as the successor to Windows 10 (2015). It is available as a free upgrade for devices running Windows 10 that meet its system requirements. The Windows Server counterpart, Server 2025, was released in 2024. Windows 11 is the first major version of Windows without a corresponding mobile edition, following the discontinuation of Windows 10 Mobile and is implemented to mobile devices with different form factors, screen sizes and CPU architectures (including tablets and handheld game consoles with smaller screen sizes) as a unified edition of Windows. As of October 14, 2025, Windows 11 is the only fully supported consumer-oriented version of Windows.

Windows 11 introduced a redesigned Windows shell influenced by elements of the canceled Windows 10X project, including a centered Start menu, a separate "Widgets" panel replacing live tiles, and new window management features. It also incorporates gaming technologies from the Xbox Series X and Series S, such as Auto HDR and DirectStorage on supported hardware. The Chromium-based Microsoft Edge remains the default web browser, replacing Internet Explorer, while Microsoft Teams is integrated into the interface. Microsoft also expanded support for third-party applications in the Microsoft Store, including limited compatibility with Android apps through a partnership with the Amazon Appstore.