Windows Vista.

Windows Vista
Part of the Microsoft Windows family
Screenshot of Windows Vista Ultimate

Windows Vista is an operating system expressed in several variations developed byMicrosoft for use on personal computers, including home and business desktops,laptops, tablet PCs, and media center PCs. Prior to its announcement on July 22, 2005, Windows Vista was known by its codename "Longhorn. 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, and was made available for purchase and download from Microsoft's website. The release of Windows Vista came more than five years after the introduction of its predecessor,Windows XP, the longest time span between successive releases of Microsoft Windows desktop operating systems. It was succeeded by Windows 7 which was released to manufacturing on July 22, 2009, and for the general public on October 22, 2009.

Windows Vista contains many changes and new features, including an updatedgraphical user interface and visual style dubbed Aero, a redesigned search function, multimedia tools including Windows DVD Maker, and redesigned networking, audio, print, and display sub-systems. Vista aims to increase the level of communication between machines on a home network, using peer-to-peer technology to simplify sharing files and media between computers and devices. Windows Vista includes version 3.0 of the .NET Framework, allowing software developers to write applications without traditional Windows APIs.

Microsoft's primary stated objective with Windows Vista has been to improve the state of security in the Windows operating system. One common criticism of Windows XP and its predecessors is 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

media, lack of compatibility with some pre-Vista hardware and software, and the number of authorization prompts for User Account Control. As a result of these and other issues, Windows Vista had seen initial adoption and satisfaction rates lower than Windows XP.However, with an estimated 330 million Internet users as of January 2009, it had been announced that Vista usage had surpassed Microsoft’s pre-launch two-year-out expectations of achieving 200 million users. At the release of Windows 7 (October 2009), Windows Vista (with approximately 400 million Internet users) was the second most widely used operating system on the Internet with an approximately 18.6% market share, the most widely used being Windows XP with an approximately 63.3% market share. As of the end of February 2010, Windows Vista's market share is down to 20.07%, having peaked at 22.64% in August 2009.

While these new features and security improvements have garnered positive reviews, Vista has also been the target of much criticism and negative press. Criticism of Windows Vista has targeted its high system requirements, its more restrictive licensing terms, the inclusion of a number of new digital rights managementtechnologies aimed at restricting the copying of protected digital Microsoft began work on Windows Vista, known at the time by its codename Longhorn, in May 2001, five months before the release of Windows XP. It was originally expected to ship sometime late in 2003 as a minor step between Windows XP and Blackcomb, which was planned to be the company's next major operating system release. 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 to build updates to Windows XP and Windows Server 2003 to strengthen security. Faced with ongoing delays and concerns about feature creep, Microsoft announced on August 27, 2004, that it had revised its plans. The original Longhorn, based on the Windows XP source code, was scrapped, and Longhorn's development started anew, building on the Windows Server 2003 Service Pack 1 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 which is programmed in C, C++ and Assembly. After Longhorn was named Windows Vista in July 2005, an unprecedented beta-test program was started, involving hundreds of thousands of volunteers and companies. In September of that year, Microsoft started releasing regular Community Technology Previews (CTP) to beta testers. The first of these was distributed at the 2005 Microsoft Professional Developers Conference, and was subsequently released to 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