Windows XP


Windows XP is a major release of Microsoft's Windows NT operating system. It was released to manufacturing on August 24, 2001, and later to retail on October 25, 2001. It is a direct successor to Windows 2000 for high-end and business users and Windows Me for home users.
Development of Windows XP began in the late 1990s under the codename "Neptune", built on the Windows NT kernel and explicitly intended for mainstream consumer use. An updated version of Windows 2000 was also initially planned for the business market. However, in January 2000, both projects were scrapped in favor of a single OS codenamed "Whistler", which would serve as a single platform for both consumer and business markets. As a result, Windows XP is the first consumer edition of Windows not based on the Windows 95 kernel or MS-DOS.
Upon its release, Windows XP received critical acclaim, noting increased performance and stability, a more intuitive user interface, improved hardware support and expanded multimedia capabilities. Windows XP and Windows Server 2003 were succeeded by Windows Vista and Windows Server 2008, released in 2007 and 2008, respectively.
Mainstream support for Windows XP ended on April 14, 2009, and extended support ended on April 8, 2014. Windows Embedded POSReady 2009, based on Windows XP Professional, received security updates until April 2019. The final security update for Service Pack 3 was released on May 14, 2019. Unofficial methods were made available to apply the updates to other editions of Windows XP. Microsoft has discouraged this practice, citing compatibility issues.
, globally, 0.43% of Windows PCs and 0.1% of all devices across all platforms continue to run Windows XP.

Development

In the late 1990s, initial development of what would become Windows XP was focused on two individual products: "Odyssey", which was reportedly intended to succeed the future Windows 2000 and "Neptune", which was reportedly a consumer-oriented operating system using the Windows NT architecture, succeeding the MS-DOS-based Windows 98.
However, the projects proved to be too ambitious. In January 2000, shortly prior to the official release of Windows 2000, technology writer Paul Thurrott reported that Microsoft had shelved both Neptune and Odyssey in favor of a new product codenamed "Whistler", named after Whistler, British Columbia, as many Microsoft employees skied at the Whistler-Blackcomb ski resort. The goal of Whistler was to unify both the consumer and business-oriented Windows lines under a single, Windows NT platform. Thurrott stated that Neptune had become "a black hole when all the features that were cut from Windows Me were simply re-tagged as Neptune features. And since Neptune and Odyssey would be based on the same code-base anyway, it made sense to combine them into a single project".
At PDC on July 13, 2000, Microsoft announced that Whistler would be released during the second half of 2001, and also unveiled the first preview build, 2250, which featured an early implementation of Windows XP's visual styles system and interface changes to Windows Explorer and the Control Panel.
Microsoft released the first public beta build of Whistler, build 2296, on October 31, 2000. Subsequent builds gradually introduced features that users of the release version of Windows XP would recognize, such as Internet Explorer 6.0, the Microsoft Product Activation system, and the Bliss desktop background.
Whistler was officially unveiled during a media event on February 5, 2001, under the name Windows XP, where XP stands for "eXPerience".

Release

In June 2001, Microsoft indicated that it was planning to spend at least US$1 billion on marketing and promoting Windows XP, in conjunction with Intel and other PC makers. The theme of the campaign, "Yes You Can", was designed to emphasize the platform's overall capabilities. Microsoft had originally planned to use the slogan "Prepare to Fly", but it was replaced because of sensitivity issues in the wake of the September 11 attacks.
On August 24, 2001, Windows XP build 2600 was released to manufacturing. During a ceremonial media event at Microsoft Redmond Campus, copies of the RTM build were given to representatives of several major PC manufacturers in briefcases, who then flew off on decorated helicopters. While PC manufacturers would be able to release devices running XP beginning on September 24, 2001, XP was expected to reach general retail availability on October 25, 2001. On the same day, Microsoft also announced the final retail pricing of XP's two main editions, "Home" and "Professional".

New and updated features

User interface

While retaining some similarities to previous versions, Windows XP's interface was overhauled with a new visual appearance, with an increased use of alpha compositing effects, drop shadows, and "visual styles", which completely changed the appearance of the operating system. The number of effects enabled are determined by the operating system based on the computer's processing power, and can be enabled or disabled on a case-by-case basis. XP also added ClearType, a new subpixel rendering system designed to improve the appearance of fonts on liquid-crystal displays. A new set of system icons was also introduced. The default wallpaper, Bliss, is a photo of a landscape in the Napa Valley outside Napa, California, with rolling green hills and a blue sky with stratocumulus and cirrus clouds.
The Start menu received its first major overhaul in XP, switching to a two-column layout with the ability to list, pin, and display frequently used applications, recently opened documents, and the traditional cascading "All Programs" menu. The taskbar can now group windows opened by a single application into one taskbar button, with a popup menu listing the individual windows. The notification area also hides "inactive" icons by default. A "common tasks" list was added, and Windows Explorer's sidebar was updated to use a new task-based design with lists of common actions; the tasks displayed are contextually relevant to the type of content in a folder.
Fast user switching allows additional users to log into a Windows XP machine without existing users having to close their programs and log out. Although only one user at the time can use the console, previous users can resume their session once they regain control of the console. [|Service Pack 2] and Service Pack 3 also introduced new features to Windows XP post-release, including the Windows Security Center, Bluetooth support, Data Execution Prevention, Windows Firewall, and support for SDHC cards that are larger than 4 GB and up to 32 GB.

Infrastructure

Windows XP uses prefetching to improve startup and application launch times. It also became possible to revert the installation of an updated device driver, should the updated driver produce undesirable results.
A copy protection system known as Windows Product Activation was introduced with Windows XP and its server counterpart, Windows Server 2003. All non-enterprise Windows licenses must be tied to a unique ID generated using information from the computer hardware, transmitted either via the internet or a telephone hotline. If Windows is not activated within 30 days of installation, the OS will cease to function until it is activated. Windows also periodically verifies the hardware to check for changes. If significant hardware changes are detected, the activation is voided, and Windows must be re-activated.

Networking and internet functionality

Windows XP was originally bundled with Internet Explorer 6, Outlook Express 6, Windows Messenger, and MSN Explorer. New networking features were also added, including Internet Connection Firewall, Internet Connection Sharing integration with UPnP, NAT traversal APIs, Quality of Service features, IPv6 and Teredo tunneling, Background Intelligent Transfer Service, extended fax features, network bridging, peer to peer networking, support for most DSL modems, IEEE 802.11 connections with auto configuration and roaming, TAPI 3.1, and networking over FireWire. Remote Assistance and Remote Desktop were also added, which allow users to connect to a computer running Windows XP from across a network or the Internet and access their applications, files, printers, and devices or request help. Improvements were also made to IntelliMirror features such as Offline Files, roaming user profiles, and folder redirection.

Backward compatibility

To enable running software that targets or locks out specific versions of Windows, "Compatibility mode" was added. It allows pretending a selected earlier version of Windows to software, starting at Windows 95. This feature was first introduced in Windows 2000 Service Pack 2 five months before Windows XP's release, being backported from pre-release Windows XP builds. This implementation is hidden by default and must be activated by the Register Server utility, and only offers it to users under the Administrators group. It also has less options for compatibility settings. Windows XP came with a complete, finalized version of the one from Windows 2000 Service Pack 2, being included out-of-the-box without requiring any manual activation and also grants access to regular users.

Other features