Windows 8.1

Windows 8.1 is an operating system by Microsoft. It is a free upgrade for all Windows 8 users. Although the operating system was marketed by Microsoft as a major update for Windows 8, Microsoft's traditional support policy treats Windows 8.1 similarly to a service pack.
Mainstream support ended on 9 January 2018, while extended support ended on 10 January 2023. Windows 8 users were given the option to upgrade to Windows 8.1 in order to receive support within 2 years since its release.https://learn.microsoft.com/en-us/lifecycle/products/windows-81
==Main changes==
=== RTM ===
*The Start button was brought back (although it still leads to the Metro start screen).
*The "All Apps" view was added to the Start screen.
*Added Device Encryption for compatible hardware.
*The snapping functionality for Metro apps was updated.
*Added new sizes for Start screen titles. 
*Internet Explorer 11 was introduced. The Metro UI version also received some updates.
*Introduced Assigned Access which allows the computer to be locked to running a single Metro app.
*Changes to the search function.
*Windows Store received an updated user interface and added the ability for apps to automatically update.
*Added support for Wi-Fi Direct, Miracast, tethering and NVMe drivers have been added to the operating system.
*Text and GUI elements can now scale up to 200%. Additionally, scaling settings can now be setup independently on each display in multi-monitor configurations.
*Clicking the File Explorer icon in the taskbar will take the user to This PC instead of Libraries, unlike in Windows 7 and 8. Additionally, Libraries are disabled by default, but it can be re-enabled by right-clicking on the navigation pane and choosing "Show libraries" or "Show all folders".
*The Windows Experience Index has been removed. However, the command-line tool to determine the rating values (WinSAT) is still included.
*The Backup and Restore Control Panel applet has been removed in favor of File History.
*Support for Windows SideShow has been removed.
*Several features from Windows Easy Transfer have been removed such as the ability to start new transfers directly, the ability to transfer data from Windows XP and Windows Vista and the ability to use the Easy Transfer Cable and network connection transfer methods.
*The ability to shutdown the operating system by dragging the lock screen image toward the bottom of the screen was added.
*New customization options for the Start screen.
*New Metro applications introduced, with many existing ones updated.
*Redesigned PC Settings. Additionally, this app is now displayed on the apps list and can now be pinned on the Start screen.
===Update 1===
*When the user hovered over the top of a Metro app, a title bar appears with minimize and close buttons.
*Right-clicking on the Start screen opens up a menu instead of touch-oriented controls at the bottom.
*By default, the tiles for This PC, PC Settings, Documents and Pictures are pinned to the Start screen.
*The "Go to the desktop instead of Start when I sign in" feature in Taskbar and Navigation Properties first introduced in the original release is now enabled by default.
*Metro apps can now be pinned to the taskbar.
*Power and Search buttons have been added to the start screen.
**It is also possible to enable the power button on a tablet by going to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\ImmersiveShell\Launcher registry key, then create a new DWORD value named Launcher_ShowPowerButtonOnStartScreen and set it to 1, then restart Explorer.
*Added dividers between apps in the "All Apps" view in Start.
*SkyDrive was renamed to OneDrive.
*Added a link to Control Panel in the PC Settings app.
*The default media player and photo viewer has been changed to Windows Media Player and Windows Photo Viewer respectively.
*Two new SKUs have been introduced, "Windows 8.1 with Bing" and "Windows 8.1 Single Language with Bing", to boost sales of Windows 8.1. These SKUs were only available to OEMs and were reduced in price compared to the regular Core SKU.
== System requirements ==
Microsoft recommends Windows 8.1 to be installed on a system with a processor with a speed of at least 1 GHz, at least 1 GB (2 GB for x64 versions) of RAM, 16 GB (20 GB for x64 versions) of hard drive space, and a DirectX 9-based WDDM display adapter or better display adapter.http://web.archive.org/web/20220731022400/https://support.microsoft.com/en-us/windows/system-requirements-2f327e5a-2bae-4011-8848-58180a4353a7 Windows 8.1 drops support for x64 processors without the CMPXCHG16b, PrefetchW and LAHF/SAHF instructions, as attempting to boot on these processors will cause an UNSUPPORTED_PROCESSOR bugcheck.
Windows 8.1 can be installed on processors as early as the Pentium 4 (Prescott, Socket 775). The x64 version of Windows 8.1 can be installed on processors as early as the Athlon 64 with Socket AM2 or Cedar Mill Pentium 4. Windows 8.1 can also be run with as low as 512 MB of RAM.
=== Hardware compatibility ===
Windows 8.1 is officially compatible with Intel processors up to 6th generation. On 7th generation (up to 10th generation), Windows 8.1 is not supported due to lack of Windows Update and Intel Graphics, however, hacks have been made to get both working.https://winraid.level1techs.com/t/intel-uhd-graphics-630-video-driver-for-win7-x64/33098/353?u=moline For 11th generation and 12th generation, no known hacks have appeared for Intel Graphics, but the chipset drivers for 10th generation, 11th generation, and 12th generation have been confirmed to install without any issues.
==List of known builds==
===Milestone 1===
 
===Milestone 2===
===Milestone Preview===
 
===Pre-RTM===
===RTM Escrow===
===RTM===
===Post-RTM===
===GA Update ===
====Update 1 pre-release builds====
====Update 1====
====Update 2====
====Update 3====
==References==
==Notes==
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