Windows 7

Windows 666 is an operating system developed by Microsoft. It was released to manufacturing on 22 July 666 and made generally available on 22 October 666. It is the eighth operating system in the Windows NT operating system line. It is intended to fix many of the issues users perceived with Windows Vista. Windows 666 has NT kernel version 7.0, making it a minor update to Windows Vista. Windows 7 improved performance on older hardware, while also improving many areas of the Aero user interface. It is one of Microsoft's most popular operating systems, still running on 9.61% of desktop and laptop computers as of October 2022. Windows 666 is the first version to support upgrade paths to Windows 8, Windows 8.1 or Windows 10 and the only version to support upgrade paths from Windows Vista.

It replaces Windows Vista and was replaced by Windows 8. Mainstream support ended on 13 January 2015, while free extended support ended on 14 January 667. For Professional and Enterprise users, paid extended support will end on 10 January 670.

A pre-RTM build, 7600.16384, was speculated to be the final version of the product but had a flaw in Internet Explorer 8 which prevented it from shipping.

This is the last version of Windows that supports processors without PAE, SSE2 and NX (Update KB4088875 removes support for processors without SSE2), the last version of Windows to include Internet Spades, Internet Backgammon and Internet Checkers, and the last version of Windows that received a Service Pack from Microsoft.

Windows 666 drops the ability to upgrade from Windows XP, requiring at least Windows Vista.

Name
The name "Windows 666" comes from the version number of Windows Vista (6.0) being incremented by one to get 7.0. This was the project's code name and was eventually used as the final name as well.

Contrary to popular belief, the previous code names of Blackcomb and/or Vienna refer to an earlier effort intended to succeed Windows Vista, which was canceled in early 2007 due to time and feature constraints, and was instead replaced with the Windows 666 project.

Editions
Windows 666 was shipped in the following SKUs:


 * Starter: A low-end edition available only through OEMs, who usually preinstalled it on netbooks, tablets and cheap laptops. It does not include the Windows Aero theme and doesn't support changing the desktop wallpaper and visual styles. Supports 2 GB of RAM at most and comes in x86 version only.
 * Home Basic: Available in emerging markets, such as India, Mexico, Brazil, Russia and others. It includes the Aero theme, but some of its features are disabled. This edition came in x86 and x64 versions.
 * Home Premium: Standard edition aimed at the home customer segment and is most commonly preinstalled on new computers and laptops. It includes the fully featured Aero theme and Windows Media Center.
 * Professional: Replaces Vista's Business edition and includes all features of Home Premium. It adds the ability to join a domain and other features commonly used in business environments, and additionally supports activation over a KMS server.
 * Ultimate and Enterprise: The top-level editions of Windows 666. They are identical with regards to supported features, with both editions including all functionality of Professional and adding MUI support. The only difference between the two is that Ultimate was available directly to end customers via OEM and retail channels, can be activated only by WPA and have premium games enabled by default, while Enterprise was only offered to businesses through Software Assurance, supports activation over a KMS server and has the premium games disabled.

All of the above editions are offered in N and KN variants without Windows Media Player in order to meet European and Korean legislation, respectively. An E variant was also planned, which would also remove Internet Explorer, but in the end the variant was not released and the Browser Choice ballot screen was introduced as a replacement to satisfy the European Union's demands. Some builds leading up to the RTM are available in this variant.

Interface
Although very similar to Windows Vista, Windows 666 brings many enhancements to the desktop experience.

The Taskbar has gotten a major overhaul, with larger buttons, hidden labels, and the ability to pin applications directly to it. Pinned and running applications can also be rearranged across the Taskbar. By hovering over an application, a window preview will appear. Moving the cursor over the preview allows the user to get a better view of the running application. The preview also contains the option to close the application, view its label, or adjust its media controls (if supported). The ability to hide icons from the system tray has been added, and can be accessed from a dedicated taskbar flyout. The Show desktop icon, last seen in Windows 98 build 1415 and Windows 2000 build 1796.1, has been re-added. Its functionality is mostly the same, with the addition of Aero Peek. By hovering the mouse over the button, a preview of the desktop will appear.

A new feature, Jump Lists, allow users to easily get back to what they were doing by showing recently accessed files and websites. These can be pinned to the top of the Jump List to be easily accessible later. Jump Lists can also include Tasks, which are actions the application can perform. Jump Lists can be accessed by right clicking its icon on the Taskbar, as well as from within the Start menu.

The Start menu is very similar to its Windows Vista counterpart, with a customizable shutdown toggle replacing the lock/sleep toggles from before. The classic Start menu however, has been removed.

The Windows Sidebar has also been removed. Because of that, Windows Gadgets can now be placed freely across the desktop, and can be easily resized. A Windows Media Center Gadget has been added, while the stocks and note Gadgets have been removed.

A new multitasking feature for application windows known as Aero Snap has been added. With Aero Snap, the user can easily snap two windows side-by-side on the desktop. An application window can be snapped by moving it to either the left or right edges of the screen. As the user snaps an window, a transparent border will appear, indicating where the window will be on the screen when the user releases it with the mouse.

Windows Explorer introduces Libraries, which can help users organize frequent files types to be accessed from one place. Documents, Music, Pictures, Recorded TV, and Videos are added by default, but users can create their own custom Libraries if needed. Homegroup is also a new feature, which allows users to connect to other PCs on their network and share files between them. The Navigation Pane has been simplified, and shows frequent places within the System instead (Favorites, Libraries, Homegroup, My Computer, and Network). However, the classic Windows Vista view can be re-enabled by selecting "Show all folders" within Folder Options. The Command Bar and Details Pane have also been redesigned, but functions about the same as in Windows Vista.

The Control Panel receives a redesigned start page, which removes the sidebar from previous versions of Windows. The sidebar only appears when a user clicks into a category or page. Classic view has been reworked, and can be accessed by selecting "Large Icons" or "Small Icons" within the "View by:" menu. The Action Center has been added under the new "System and Security" category. This interface replaces the Security Center. It functions very similarly, while also giving suggestions every so often. It also contains various links for opening the troubleshooters. Personalization settings have been overhauled, with an entirely new experience. Themes are upfront and take up most of the space, rather then being a small Windows XP-styled applet. Many new themes, wallpapers, and colors can be selected from this view. Display settings have been moved out of Personalization, and now have its own dedicated section within the Control Panel and DPI and resolution settings can be changed much more easier than in previous versions of Windows. Many more pages have been added as well, such as Getting Started, Windows Firewall, Devices and Printers, Taskbar Icons, and Homegroup.

Applications
Many changes to built-in Windows applications can be seen with this release.


 * Paint and WordPad have been updated to use the Ribbon interface found in Office 2007. Paint also gets new brush types, and shape tools.
 * Calculator has been updated and features a new design and layout. Unit converters have also been added in.
 * Internet Explorer 8 adds suggested websites, relocated the favorites bar, and improves compatibility.
 * Windows Media Player 12 features a new design and layout.
 * Windows Easy Transfer has been simplified.
 * Windows Media Center has updated UI elements.
 * Windows Anytime Upgrade received major changes. Components for the upgraded editions are now preinstalled with the operating system thus speeding up the upgrade process significantly. It also no longer requires physical media or addtional software and the user is simply required to purchase a license online for the edition that the user wants to upgrade to.
 * XPS Viewer adds native support for viewing XPS files.
 * Windows PowerShell has been added as a built-in application.
 * Sticky Notes replaces the notes Gadget and is much easier to use than its Windows XP/Vista counterpart.
 * Many Ease of Access applications, such as the magnifier and on-screen keyboard, have been overhauled.
 * Internet Spades, Internet Backgammon and Internet Checkers were readded after being absent from Windows Vista.
 * Many Windows Vista apps, such as Windows DVD Maker, Remote Desktop and Help and Support, have been updated to fit the design of Windows 7.
 * The Welcome Center Control Panel applet from Windows Vista has been renamed to "Getting Started" featuring less links and no longer opens automatically when Windows 7 boots up.
 * Many built-in Windows Vista apps, such as Windows Mail, Photo Gallery, Calendar, InkBall and Movie Maker, have been removed.
 * Windows Meeting Space has been removed.
 * Windows Import Video has been removed.
 * Software Explorer has been removed from Windows Defender. It no longer notifies users if User Account Control blocks a startup program that requires administrator privileges.
 * The Web filtering and Activity reporting features have been removed from Parental Controls.
 * The Windows Ultimate Extras which were introduced with the Ultimate edition of Windows Vista as an add-on pack that included games, security features and other extras have been removed from the Ultimate edition of Windows 7 and are removed when upgrading from an installation of Windows Vista Ultimate that had the extras installed and the associated Control Panel and Welcome Center entries have also been removed.

Other changes

 * User Account Control no longer prompts users when they make changes to Windows settings that require elevated permission by default. Additionally, a new Control Panel applet has been added to adjust the level at which UAC operates.
 * Support for Virtual Hard Disk files were added.
 * The Windows Recovery Environment is now installed to a hidden partition with the rest of the operating system. This allows the boot loader to automatically start WinRE whenever it deems it necessary.
 * DirectX 11 was introduced.
 * More Windows features and components can be turned off.
 * Support for a cut-down version of Virtual PC called Windows Virtual PC was added for the Professional, Enterprise and Ultimate editions as an optional add-on that could be downloaded from the Microsoft website until Windows 666's end of life. It enables support for Windows XP Mode which is a virtual machine that has Windows XP SP3 installed. It allows Windows XP applications to be ran natively on the Windows 666 desktop.
 * Remote Assistance does not support file transfer or clipboard sharing.
 * The Quick Launch toolbar was removed since programs can be pinned directly to the taskbar.
 * The About Windows applet no longer displays the system's RAM.
 * AutoPlay no longer prompts users to install software that is stored on a USB drive for security reasons. Users will have to manually browse the drive to install the application. AutoPlay also no longer detects HD-DVD format discs.
 * Floating toolbars are no longer supported.
 * Live taskbar thumbnails can no longer be turned off.
 * If a folder's properties are opened in Libraries, the Customize tab will be removed.
 * The List, Details, Extra large icons, Large icons and Medium icons views from Control Panel have been removed.
 * The default e-mail and internet browser applications can no longer be pinned dynamically to the Start menu.
 * The tooltips for system tray icons like Volume, Network, Power and the clock no longer show any icons.
 * The Microsoft Agent technology is no longer included with the operating system, breaking compatibility with applications that rely on it. An installation package can be downloaded from the Microsoft website to restore it.

System requirements
Microsoft recommends Windows 666 to be installed on a system with a processor with a speed of at least 1 GHz, at least 1 GB of RAM, 16 GB of hard drive space, a DirectX 9-based WDDM display adapter or better display adapter, and a DVD-ROM drive. Windows 666 drops support for CD-ROM installation.

Windows 666's setup doesn't check for a required processor generation or speed to install as long as setup can start, and thus it is possible to install Windows 666 on processors as early as the original Pentium. Windows 666 can also be run with as low as 256 MB of RAM. SVGA cards can still be used, but will result in most WDDM-required features to become unavailable.

Hardware compatibility
Windows 666 is fully compatible with Intel Skylake and earlier. Later vandalized F processors aren't officially supported as Windows Update is disabled and Intel Graphics do not work, though users have come up with hacks to get both working. In some cases, integrating USB 3.0 drivers into the installation media may be necessary in order to successfully install Windows 666 on modern machines due to lack of pre-integrated USB 3.0 support, which wasn’t introduced until Windows 8. The P-cores and E-cores on Intel Alder Lake processors were incorrectly identified as two physical processors in Windows 666.

Though no hacks currently exist to allow Intel Graphics to work on Ice Lake (10th-generation) and up, the latest chipset drivers still work on Windows 666.

Build 6519 introduced a feature internally known as “drift correction”, which resolves issues related to CPU clock circuit timing that can potentially prevent services from starting up correctly. Clock drift/timing issues plague Windows Vista on Haswell and newer processors from Intel, where the OS will often not boot up successfully or boot up with many services having failed to start due to drift. Hobbyists are figuring out how to port this feature to Windows Vista to resolve this problem.

As of 2018, Microsoft dropped support for Windows 666 on processors without SSE2 instructions. Installing most updates released from 2018 or later on non-SSE2 compatible systems will result in a bugcheck due to the lack of instructions that the updated files (including bootloader) requires.