Windows Vista

Windows Vista is a line of graphical operating systems used on personal computers, including home and business desktops, notebook computers, Tablet PCs, and media centers. Prior to its announcement on July 22, 2005, Windows Vista was known by its codename "Longhorn".[1] Development was completed on November 8, 2006; over the following three months it was released in stages to computer hardware and software manufacturers, business customers, and retail channels. On January 30, 2007, it was released worldwide to the general public,[2] and was made available for purchase and downloading from Microsoft's web site.[3] The release of Windows Vista comes more than five years after the introduction of its predecessor, Windows XP, making it the longest time span between two releases of Microsoft Windows.

Windows Vista contains hundreds of new features; some of the most significant include an updated graphical user interface and visual style dubbed Windows Aero, improved searching features, new multimedia creation tools such as Windows DVD Maker, and completely redesigned networking, audio, print, and display sub-systems. Vista also aims to increase the level of communication between machines on a home network using peer-to-peer technology, making it easier to share files and digital media between computers and devices. For developers, Vista includes version 3.0 of the .NET Framework, which aims to make it significantly easier for developers to write high-quality applications than with the traditional Windows API.

Microsoft's primary stated objective with Windows Vista, however, has been to improve the state of security in the Windows operating system.[4] One common criticism of Windows XP and its predecessors has been their commonly exploited security vulnerabilities and overall susceptibility to malware, viruses and buffer overflows. In light of this, Microsoft chairman Bill Gates announced in early 2002 a company-wide 'Trustworthy Computing initiative' which aims to incorporate security work into every aspect of software development at the company. Microsoft stated that it prioritized improving the security of Windows XP and Windows Server 2003 above finishing Windows Vista, thus delaying its completion.[5]

Windows Vista has been the target of a number of negative assessments by various groups. Criticism of Windows Vista has included protracted development time, more restrictive licensing terms, the inclusion of a number of new Digital Rights Management technologies aimed at restricting the copying of protected digital media, and the usability of other new features such as User Account Control.

Microsoft started work on their plans for Windows Vista ("Longhorn") in 2001, prior to the release of Windows XP. It was originally expected to ship sometime late in 2003 as a minor step between Windows XP (codenamed "Whistler") and "Blackcomb" (now known as Windows "Vienna"). Gradually, "Longhorn" assimilated many of the important new features and technologies slated for "Blackcomb," resulting in the release date being pushed back several times. Many of Microsoft's developers were also re-tasked with improving the security of Windows XP. Faced with ongoing delays and concerns about feature creep, Microsoft announced on August 27, 2004 that it was making changes. The original "Longhorn," based on the Windows XP source code, was scrapped, and Vista development started anew, building on the Windows Server 2003 codebase, and re-incorporating only the features that would be intended for an actual operating system release. Some previously announced features such as WinFS were dropped or postponed, and a new software development methodology called the "Security Development Lifecycle" was incorporated in an effort to address concerns with the security of the Windows codebase. After "Longhorn" was named Windows Vista, an unprecedented beta-test program was started, involving hundreds of thousands of volunteers and companies. In September 2005, Microsoft started releasing regular Community Technology Previews (CTP) to beta testers. The first of these was distributed among 2005 Microsoft Professional Developers Conference attendees, and was subsequently released to Microsoft Beta testers and Microsoft Developer Network subscribers. The builds that followed incorporated most of the planned features for the final product, as well as a number of changes to the user interface, based largely on feedback from beta testers. Windows Vista was deemed feature-complete with the release of the "February CTP," released on February 22, 2006, and much of the remainder of work between that build and the final release of the product focused on stability, performance, application and driver compatibility, and documentation. Beta 2, released in late May, was the first build to be made available to the general public through Microsoft's Customer Preview Program. It was downloaded by over five million people. Two release candidates followed in September and October, both of which were made available to a large number of users.

While Microsoft had originally hoped to have the operating system available worldwide in time for Christmas 2006, it was announced in March 2006 that the release date would be pushed back to January 2007, so as to give the company – and the hardware and software companies which Microsoft depends on for providing device drivers – additional time to prepare.

Through much of 2006, analysts and bloggers had speculated that Windows Vista would be delayed further, owing to anti-trust concerns raised by the European Commission and South Korea, and due to a perceived lack of progress with the beta releases. However, with the November 8, 2006 announcement of the completion of Windows Vista, Microsoft's most lengthy operating system development project came to an end.

Core technologies

Windows Vista is intended to be a technology-based release, to provide a solid base to include technologies, many of which will be related to how the system functions, and hence not readily visible to the user. An example of this is the restructuring of the architecture of the audio, print, display, and networking subsystems; while the results of this work will be visible to software developers, end-users will only see what appear to be evolutionary changes in the user interface.

Vista includes technologies such as ReadyBoost and ReadyDrive which employ fast flash memory (located on USB drives and hybrid hard disk drives respectively) to improve system performance by caching commonly-used programs and data. This manifests itself in improved battery life on notebook computers as well, since a hybrid drive can use the Flash memory to cache the data currently in use by the OS and/or other applications, spinning down the disc platters till some fresh data is required. Another new technology called SuperFetch utilizes machine learning techniques to analyze usage patterns in order to allow Windows Vista to make decisions about what application and content should be present in system memory at any given time.

As part of the redesign of the networking architecture, IPv6 has been incorporated into the operating system, and a number of performance improvements have been introduced, such as TCP window scaling. Windows Vista includes a more comprehensive support for Wireless Networks, compared to previous versions of Windows.

For graphics, Vista introduces a new Windows Display Driver Model, as well as major revisions to Direct3D. The new driver model facilitates the new Desktop Window Manager, which provides the tearing-free desktop and special effects that are the cornerstones of Windows Aero. WDDM's current version 1.0 is able to offload rudimentary tasks to the GPU, install drivers without requiring a system reboot and seamlessly recover from rare driver errors due to illegal application behavior. The next version is going to require an entirely new generation of GPUs, which nVidia and ATI are working on. Direct3D 10, developed in conjunction with major display driver manufacturers, is a new architecture with more advanced shader support, and allows the graphics processing unit to render more complex scenes without assistance from the CPU. It features improved load balancing between CPU and GPU and also optimizes data transfer between them.

At the core of the operating system, many improvements have been made to the memory manager, process scheduler, heap manager, and I/O scheduler. A Kernel Transaction Manager has been implemented that gives applications the ability to work with the file system and registry using atomic transaction operations.