Windows RT

Windows RT

Version of the Windows NT operating system
Screenshot of Windows RT 8.1 Update 3 running on a Surface RT, showing Start menu and system specifications
Developer	Microsoft
Final release	6.3.9600 Update 3 (Windows RT 8.1 Update 3) / January 10, 2023; 15 months ago (2023-01-10)[1][2]
Platforms	ARMv7
Kernel type	Hybrid (Windows NT)
Succeeded by	Windows 10 S Windows 10 (ARM64), version 1709
Official website	windows.microsoft.com/en-us/windows/rt-welcome
Support status
Windows RT (8.0) is unsupported as of January 12, 2016. Customers had to update to Windows RT 8.1 to continue to receive support.[3] Mainstream support for Windows RT 8.1 ended on January 9, 2018 Extended support for Windows RT 8.1 ended on January 10, 2023[3][4]

Part of a series of articles on
Windows 8
Features Editions Windows RT Windows 8.1 Windows Server 2012 Windows Server 2012 R2 Windows Phone 8 Windows Phone 8.1 Windows Store Removed features
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Windows RT is a mobile operating system developed by Microsoft. It is a version of Windows 8 or Windows 8.1 built for the 32-bit ARM architecture (ARMv7).^[6] First unveiled in January 2011 at Consumer Electronics Show, the Windows RT 8 operating system was officially launched alongside Windows 8 on October 26, 2012, with the release of three Windows RT-based devices, including Microsoft's original Surface tablet. Unlike Windows 8, Windows RT is only available as preloaded software on devices specifically designed for the operating system by original equipment manufacturers (OEMs).

Microsoft intended for devices with Windows RT to take advantage of the architecture's power efficiency to allow for longer battery life, to use system-on-chip (SoC) designs to allow for thinner devices and to provide a "reliable" experience over time. In comparison to other mobile operating systems, Windows RT also supports a relatively large number of existing USB peripherals and accessories and includes a version of Microsoft Office 2013 optimized for ARM devices as pre-loaded software. However, while Windows RT inherits the appearance and functionality of Windows 8, it has a number of limitations; it can only execute software that is digitally signed by Microsoft (which includes pre-loaded software and Windows Store apps), and it lacks certain developer-oriented features. It also lacks support for running applications designed for x86 processors, which were the main platform for Windows at the time. This would later be corrected with the release of Windows 10 version 1709 for ARM64 devices.

Windows RT was released to mixed reviews from various outlets and critics. Some felt that Windows RT devices had advantages over other mobile platforms (such as iOS or Android) because of its bundled software and the ability to use a wider variety of USB peripherals and accessories, but the platform was criticized for its poor software ecosystem, citing the early stage of Windows Store and its incompatibility with existing Windows software, and other limitations over Windows 8.

Critics and analysts deemed Windows RT to be commercially unsuccessful, citing these limitations, its unclear, uncompetitive position of sitting as an underpowered system between Windows Phone and Windows 8, and the introduction of Windows 8 devices with battery life and functionality that met or exceeded that of Windows RT devices. Improvements to Intel's mobile processors, along with a decision by Microsoft to remove OEM license fees for Windows on devices with screens smaller than 9 inches, spurred a market for low-end Wintel tablets running the full Windows 8 platform. These devices largely cannibalized Windows RT; vendors began phasing out their Windows RT devices due to poor sales, and less than a year after its release, Microsoft suffered a US$900 million loss that was largely blamed on poor sales of the ARM-based Surface tablet and unsold stock.

Only two more Windows RT devices, Microsoft's Surface 2 and the Nokia Lumia 2520 in late 2013, were released beyond the five original launch devices, and no Windows RT counterpart to the Surface Pro 3 was released due to a re-positioning of the Surface line into the high-end market, and a switch to Intel architecture for the Surface 3. These developments left Microsoft's future support of the platform in doubt. With the end of production for both Microsoft Surface 2 and Lumia 2520, Microsoft and its subsidiaries no longer manufacture any Windows RT devices.