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.

Windows 7 was intended to be an incremental upgrade to Windows Vista, addressing the previous OS's issues while maintaining hardware and software compatibility as well as fixing some of Vista's inconsistencies (such as Vista's aggressive User Account Control). Windows 7 continued improvements on the Windows Aero user interface with the addition of a redesigned taskbar that allows pinned applications, and new window management features. Other new features were added to the operating system, including libraries, the new file-sharing system HomeGroup, and support for multitouch input. A new "Action Center" was also added to provide an overview of system security and maintenance information, and tweaks were made to the User Account Control system to make it less intrusive. Windows 7 also shipped with updated versions of several stock applications, including Internet Explorer 8, Windows Media Player 12, and Windows Media Center.

Unlike Windows Vista, which received a mixed reception at launch, Windows 7 received significant positive reviews from reviewers and consumers, with critics considering the operating system to be a major improvement over its predecessor for its improved performance, intuitive interface, fewer User Account Control pop-ups, and other improvements made across the platform. Windows 7 was a major success for Microsoft; even before its official release, pre-order sales for the operating system on the online retailer Amazon.com had surpassed previous records. In just six months, over 100 million copies were sold worldwide until July 2012. By January 2018, Windows 10 surpassed Windows 7 as the most popular version of Windows worldwide. Windows 11 overtook Windows 7 as the second most popular Windows version on all continents in August 2022.

It is the final version of Microsoft Windows that supports processors without SSE2 or NX (although an update released in 2018, KB4103718, dropped support for non-SSE2 processors).

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.

Naming Windows 7 is the successor to Windows Vista, and its version name is Windows NT 6.1, compared to Vista's NT 6.0; its naming caused some confusion when it was announced in 2008. Windows president Steven Sinofsky commented that Windows 95 was the fourth version of Windows, but Windows 7 counts up from Windows NT 4.0 as it is a descendant of NT.

Development history

Background

Originally, a version of Windows codenamed "Blackcomb" was planned as the successor to Windows XP and Windows Server 2003 in 2000. Major features were planned for Blackcomb, including an emphasis on searching and querying data and an advanced storage system named WinFS to enable such scenarios. However, an interim, minor release, codenamed "Longhorn," was announced for 2003, delaying the development of Blackcomb. By the middle of 2003, however, Longhorn had acquired some of the features originally intended for Blackcomb. After three major malware outbreaks, the Blaster, Nachi, and Sobig worms exploited flaws in Windows operating systems within a short time period in August 2003, Microsoft changed its development priorities, putting some of Longhorn's major development work on hold while developing new service packs for Windows XP and Windows Server 2003. Development of Longhorn (Windows Vista) was also reset, and thus delayed, in August 2004 due to feature creep, and a number of features were cut from Longhorn after the reset. Blackcomb was renamed to Vienna in early 2006, and was later canceled in 2007 due to the scope of the project.

Launch of Windows Vista and the Windows 7 Project When released, Windows Vista was criticized for its long development time, performance issues, spotty compatibility with existing hardware and software at launch, changes affecting the compatibility of certain PC games, and unclear assurances by Microsoft that certain computers shipping with XP before launch would be "Vista Capable" (which led to a class-action lawsuit), among other critiques. As such, the adoption of Vista in comparison to XP remained somewhat low. In July 2007, reports indicated that a new project, codenamed Windows 7, would launch within three years, following the cancellation of the Vienna project. Bill Gates, in an interview with Newsweek, suggested that Windows 7 would be more "user-centric". Gates later said that Windows 7 would also focus on performance improvements. Steven Sinofsky later expanded on this point, explaining in the Engineering Windows 7 blog that the company was using a variety of new tracing tools to measure the performance of many areas of the operating system on an ongoing basis, to help locate inefficient code paths and to help prevent performance regressions. Senior Vice President Bill Veghte stated that Windows Vista users migrating to Windows 7 would not find the kind of device compatibility issues they encountered migrating from Windows XP. An estimated 1,000 developers worked on Windows 7. These were broadly divided into "core operating system" and "Windows client experience", in turn organized into 25 teams of around 40 developers on average.

In October 2008, it was announced that Windows 7 would also be the official name of the operating system. There had been some confusion over naming the product Windows 7, while versioning it as 6.1 to indicate its similar build to Windows Vista and increase compatibility with applications that only check major version numbers, similar to Windows 2000 and Windows XP both having 5.x version numbers. The first external release to select Microsoft partners came in January 2008 with Milestone 1, build 6519. Speaking about Windows 7 on October 16, 2008, Microsoft CEO Steve Ballmer confirmed compatibility between Windows Vista and Windows 7, indicating that Windows 7 would be a refined version of Windows Vista.

Demonstrations and betas At PDC 2008, Microsoft demonstrated Windows 7 with its reworked taskbar. On December 27, 2008, the Windows 7 Beta was leaked onto the Internet via BitTorrent. According to a performance test by ZDNet, Windows 7 Beta beat both Windows XP and Windows Vista in several key areas, including boot and shutdown time and working with files, such as loading documents. Other areas did not beat XP, including PC Pro benchmarks for typical office activities and video editing, which remain identical to Vista and slower than XP. On January 7, 2009, the x64 version of the Windows 7 Beta (build 7000) was leaked onto the web, with some torrents being infected with a trojan. At CES 2009, Microsoft CEO Steve Ballmer announced the Windows 7 Beta, build 7000, had been made available for download to MSDN and TechNet subscribers in the format of an ISO image. The stock wallpaper of the beta version contained a digital image of the Betta fish.

Release candidate and launch of Windows 7 The release candidate, build 7100, became available for MSDN and TechNet subscribers, and Connect Program participants on April 30, 2009. On May 5, 2009, it became available to the general public, although it had also been leaked onto the Internet via BitTorrent. The release candidate was available in five languages and expired on June 1, 2010, with shutdowns every two hours starting March 1, 2010. Microsoft stated that Windows 7 would be released to the general public on October 22, 2009, less than three years after the launch of its predecessor. Microsoft released Windows 7 to MSDN and Technet subscribers on August 6, 2009. Microsoft announced that Windows 7, along with Windows Server 2008 R2, was released to manufacturing in the United States and Canada on July 22, 2009. Windows 7 build 7600.16385.090713-1255, which was compiled on July 13, 2009, was declared the final RTM build after passing all Microsoft's tests internally. Windows 7 was finally released globally to general availability on October 22, 2009.

Features

New and changed

Among Windows 7's new features are advances in touch and handwriting recognition, support for virtual hard disks, improved performance on multi-core processors, improved boot performance, DirectAccess, and kernel improvements. Windows 7 adds support for systems using multiple heterogeneous graphics cards from different vendors (Heterogeneous Multi-adapter), a new version of Windows Media Center, a Gadget for Windows Media Center, improved media features, XPS Essentials Pack, and Windows PowerShell being included, and a redesigned Calculator with multiline capabilities including Programmer and Statistics modes along with unit conversion for length, weight, temperature, and several others. Many new items have been added to the Control Panel, including ClearType Text Tuner, Display Color Calibration Wizard, Gadgets, Recovery, Troubleshooting, Workspaces Center, Location and Other Sensors, Credential Manager, Biometric Devices, System Icons, and Display. Windows Security Center has been renamed to Action Center (Windows Health Center and Windows Solution Center in earlier builds), which encompasses both security and maintenance of the computer. ReadyBoost on 32-bit editions now supports up to 256 gigabytes of extra allocation. Windows 7 also supports images in RAW image format through the addition of Windows Imaging Component-enabled image decoders, which enables raw image thumbnails, previewing and metadata display in Windows Explorer, plus full-size viewing and slideshows in Windows Photo Viewer and Windows Media Center. Windows 7 also has a native TFTP client with the ability to transfer files to or from a TFTP server.

The taskbar has seen the biggest visual changes, where the old Quick Launch toolbar has been replaced with the ability to pin applications to the taskbar. Buttons for pinned applications are integrated with the task buttons. These buttons also enable Jump Lists to allow quick access to common tasks, and files frequently used with specific applications. The revamped taskbar also allows the reordering of taskbar buttons. To the far right of the system clock is a small rectangular button that serves as the Show desktop icon. By default, hovering over this button makes all visible windows transparent for a quick look at the desktop. In touch-enabled displays such as touch screens, tablet PCs, etc., this button is slightly (8 pixels) wider in order to accommodate being pressed by a finger. Clicking this button minimizes all windows, and clicking it a second time restores them.

Window management in Windows 7 has several new features: Aero Snap maximizes a window when it is dragged to the top, left, or right of the screen. Dragging windows to the left or right edges of the screen allows users to snap software windows to either side of the screen, such that the windows take up half the screen. When a user moves windows that were snapped or maximized using Snap, the system restores their previous state. Snap functions can also be triggered with keyboard shortcuts. Aero Shake hides all inactive windows when the active window's title bar is dragged back and forth rapidly.