The Surface RT (shown with keyboard cover attached) was the flagship Windows RT device upon its release.
In 2012 and 2013, Microsoft released versions of Windows specially designed to run on ARM-based tablets; these versions of Windows were based on Windows 8 and Windows 8.1, respectively. (The standard versions of Windows 8 and 8.1 could run on x86-based tablets without modification.) Upon the release of Windows 10 in 2015, the ARM-specific version for large tablets was discontinued; large tablets (such as the Surface Pro 4) were only released with x86 processors and could run the full version of Windows 10. Windows 10 Mobile had the ability to be installed on smaller tablets (up to eight inches); however, very few such tablets were released, and Windows 10 Mobile mainly ended up only running on smartphones until its discontinuation. In 2017, the full version of Windows 10 gained the ability to run on ARM, rendering a specific version of Windows for ARM-based tablets unnecessary.
Windows NT 4.0 Embedded – Abbreviated NTe, it is an edition of Windows NT 4.0 that was aimed at computer-powered major appliances, vending machines, ATMs and other devices that cannot be considered computers per se. It is the same system as the standard Windows NT 4.0, but it comes packaged in a database of components and dependencies, from which a developer can choose individual components to build customized setup CDs and hard disk boot images. Windows NT 4.0 Embedded includes Service Pack 5.
The first planned version of Microsoft Windows NT to have a consumer edition variant, based on the Windows 2000 codebase. A version was sent out to testers but was never released. The teams working on Neptune and Odyssey combined to work on Windows XP.
Planned to be the successor of Windows 2000. The teams working on Neptune and Odyssey combined to work on Windows XP.
Planned to be the successor of Windows Neptune and had been scheduled to be released in March 2001
Blackcomb was originally planned to be the successor of Windows XP. However, due to the large feature scope planned for Blackcomb, a smaller release codenamed "Longhorn" was planned first, and Blackcomb was delayed to 2003/2004. Both projects faced delays, but Blackcomb was still intended to be Longhorn's successor until the Blackcomb project was renamed Vienna in early 2006. Longhorn would go on to be released to consumers as "Windows Vista" in January 2007.
Vienna replaced Blackcomb and was intended as Windows Vista's successor. Vienna was eventually cancelled in favor of a new project codenamed "Windows 7" (which went on to be released in 2009 with the same name)
Microsoft had been reported as working on a new "lite" version of Windows as early as December 2018. Such a version was officially announced under the name "Windows 10X" at an event in October 2019; the operating system was intended to first launch on dual-screen devices. In May 2020, Microsoft announced that Windows 10X would instead be launching on single-screen PCs, such as laptops and 2-in-1 devices, first. However, on May 18, 2021, Microsoft announced that Windows 10X would not be launching (at least not in 2021); many of its features were rolled into Windows 11 instead.
Much of the work that was put into Andromeda was migrated into Santorini. The Surface Duo, a dual-screen Android-powered smartphone launched by Microsoft in 2020, was loosely based on the prototype hardware that had been used to test Andromeda.
^ abRetroactively renamed to Windows 10 Enterprise LTSC
^ abJanuary 10, 2023 for Intel Clover Trail based systems
^May 10, 2022 for enterprise and education editions
^Vibranium was the codename for Windows 10 version 2004 (build 19041). During the 20H2, 21H1, and 21H2 development cycles, builds were compiled under the codenames Manganese, Iron, and Cobalt, respectively. However, the versions of 20H2 and 21H1 that were released were built on top of version 2004 instead of these new builds. Windows 10 version 21H2 was similarly built on top of the Vibranium/2004 codebase instead of the Cobalt codebase; Cobalt builds were instead used as the base for Windows 11 (which had a core based on Cobalt in addition to a UI codenamed Sun Valley, and which also carries the version 21H2).
^May 9, 2023 for enterprise and education editions
^The core of Windows 11 is codenamed Cobalt; the "Sun Valley" codename refers to the UI layer of Windows 11 and is commonly used to address Windows 11 as a whole.
^July 2007 is when it was reported that the Vista's successor was codenamed "7," rather than "Vienna," indicating that Vienna's discontinuation had occurred by then. However, Vienna may have been cancelled prior to then.
^While Santorini was the general codename for Windows 10X, Centaurus was the specific codename for Windows 10X on foldable PCs and Pegasus was the codename for Windows 10X on "traditional" PCs (such as laptops or 2-in-1 computers).
^Martens, China (July 22, 2005). "Update: Microsoft's Longhorn becomes Windows Vista". IDG Communications, Inc. Retrieved June 13, 2021. Microsoft Corp. has announced the official name for its upcoming operating system, previously known under the code name Longhorn. The operating system, now due out in 2006, will be called Windows Vista
^Bowden, Zac (September 18, 2020). "Project Andromeda: The secret history of Windows on Surface Duo". Windows Central. Future US, Inc. Retrieved July 16, 2021. Microsoft had originally planned to ship CShell on Windows 10 Mobile under the codename Pheonix [sic], but that plan very quickly went away once the company decided to wind down its existing phone efforts in early 2017.