Windows XP

Template:Infobox OS Windows XP (codename Whistler, also known as Windows NT 5.1) is, as of 2005, the current desktop version of the Microsoft Windows operating system. It was made publicly available on October 25, 2001. Two editions of Windows XP are more commonly available than the others: Windows XP Home Edition which is targeted at home users and Windows XP Professional which has additional features such as dual-processor support and the ability to join a domain, a grouping of centrally managed Windows computers. The letters "XP" originate from the word "Experience." [1] (

Windows XP brought to the consumer line of Windows many features previously available only in the server- and workstation-oriented Windows NT and Windows 2000 families, such as greater stability and efficiency due to its pure 32-bit kernel, instead of the hybrid 16-bit/32-bit kernel in prior consumer versions of Windows. It also contains new technology to avoid the "DLL hell" that plagued older consumer versions of Windows, which stemmed from inefficient software management. Windows XP brings an overhaul of the graphical user interface (GUI) that Microsoft promotes as more user-friendly than the older versions of Windows.

Windows XP is also the first consumer version of Windows to use product activation to combat software piracy, and this restriction did not sit well with some privacy advocates, and indeed many home users. As of June 2005, there have been two service packs released to deliver updates and address problems with Windows XP, particularly the many high profile security issues. Spyware and adware have been a continuing problem on all versions of Windows, but the problem has become more apparent as Windows XP has matured.



Before Windows XP, Microsoft had sold two separate lines of operating systems. Windows 95, Windows 98, and Windows Me were designed for home desktop computers but did not have reliable memory protection, while Windows NT 4.0 and Windows 2000 were aimed at the corporate, professional, and server markets but were not as well-supported by game and multimedia developers. Windows XP (Windows NT version 5.1) is an evolution of Windows 2000 (Windows NT 5.0) with additional features for home users; it represents Microsoft's shift to using a single code base for all its operating system products.

Windows XP's Service Pack 2 improves on XP's integrated software firewall and introduces a new Security Center to monitor firewall, antivirus and updates. It is part of a major new Microsoft security effort following a long history of security issues and vulnerabilities. Unfortunately, XP is still not highly safe and many users object to the new restrictions on functionality placed on Internet Explorer in order to improve security.


The two major editions are Windows XP Home Edition, designed for home users, and Windows XP Professional, designed for business and power-users.

These are prominent differences between the two editions:

  • Windows XP Home Edition cannot become part of a Windows Server domain, a group of computers which are remotely managed by one or more central servers. Most businesses that use Windows have a Windows Server and a domain.
  • Windows XP Home Edition uses by default a simplified access control scheme which doesn't allow specific permissions on files to be granted to specific users under normal circumstances.

These features are present in Windows XP Professional but absent in Windows XP Home Edition:

  • Remote Desktop, software which lets users operate one PC while using another. The remotely controlled PC can be accessed via a network or over the Internet.
  • Offline Files and Folders allows a PC to automatically store a copy of files from another networked computer and work with these files while disconnected from the network.
  • Encrypting File System encrypts files stored on the computer's hard drive so they cannot be read by another user, even with physical access to the storage medium.
  • Symmetric multiprocessing, the ability to divide work between multiple processors (CPUs). Windows XP Professional supports up to two CPUs. Windows XP Home Edition does however support the Hyper-threading functionality present on some Intel microprocessors.
  • Centralized administration features, including Group Policies, Automatic Software Installation and Maintenance, Roaming User Profiles, and Remote Installation Service (RIS).
  • Clone Display allows users to "clone" their monitor onto a secondary display (a feature often used in video production). While it does support video cards with dual displays, XP Home Edition limits this feature only to extension of the primary display, and not cloning.

Windows XP for specialized hardware

Missing image
On TV Menu from MCE 2005

Microsoft has also customized Windows XP to suit different markets and there are now several different versions available.

Microsoft released four new versions of XP for specific hardware:

  • Windows XP Media Center Edition for special Media center PCs. Originally, Windows XP Media Center Edition was only available bundled with one of these computers; it could not be purchased separately. This received an update in 2003, "Windows XP Media Center Edition 2003", which added additional features such as FM radio tuning. Another update was released in 2004, and again in 2005, which was the first edition available for System Builders.
Missing image
Internet Explorer running on a Tablet PC
  • Windows XP Tablet PC Edition for specially designed notebook/laptop computers with a pen-sensitive screen supporting handwritten notes and portrait-oriented screens. It cannot be purchased separately from a Tablet PC.
  • Windows XP Embedded for specific consumer electronics, set-top boxes, kiosks/ATMs, medical devices, point-of-sale terminals, and Voice Over Internet Protocol (VoIP) components.
  • Windows XP Professional x64 Edition A version of Windows XP for systems with 64-bit processors.

Windows XP Starter Edition

Windows XP Starter Edition is a lower-cost version of Windows XP available in Asia and South America, including Russia and Brazil. It is similar to Windows XP Home, but has some features removed and some limitations added: display resolution can only be up to 800600 pixels, only three applications may be run at the same time, any application may have no more than three windows open, PC-to-PC home networking and printer sharing is not available and only a single user account is allowed. Added to the operating system are localized help features, country-specific wallpapers and screensavers and certain pre-configured settings to make it easier for novices to use.

According to a Microsoft press release, Windows XP Starter Edition is "a low-cost introduction to the Microsoft Windows XP operating system designed for first-time desktop PC users in developing countries." It is seen as an effort to fight unauthorized copying of Windows XP, and also to counter the spread of the open-source GNU/Linux operating system which has been gaining popularity in Asia and South America.

Windows XP Home (and Professional) Edition N

In March 2004, the European Commission fined Microsoft €497 million and ordered the company to provide a version of Windows without Windows Media Player, claiming Microsoft "broke European Union competition law by leveraging its near monopoly in the market for PC operating systems onto the markets for work group server operating systems and for media players". Microsoft is currently appealing the ruling. In the meantime, the company plans to offer a court-compliant version of its flagship operating system at the same price as the full version. Microsoft wanted to call this version Reduced Media Edition but EU regulators objected and suggested the Edition N name, with the N signifying "not with media player". [2] ( [3] ( [4] (

New and updated features

Windows XP introduced several new features to the Windows operating system line.

Improved device support

Windows XP provided new and/or improved drivers and user interfaces for devices compared to Windows Me and 98.

Windows Image Acquisition (WIA) replaced the traditional TWAIN support for scanners and digital cameras. [5] (;en-us;Q293356) [6] ( As TWAIN does not separate the user-interface from the driver of a device, it is difficult to provide transparent network access; whenever an application loads a TWAIN driver it is completely undetachable from the supplied manufacturer's GUI.

Still Image (STI) support is provided as a compatibility layer within the WIA subsystem.

On old versions of Windows, when users upgraded a device driver, there was a chance the new driver would be less efficient or functional than the original. Reinstalling the old driver could be a major hassle, and to avoid this quandary, Windows XP keeps a copy of an old driver when a new version is installed. If the new driver has problems, the user can return to the previous version. However, this feature does not work with printer drivers. [7] (


Fast User Switching allows another user to log in and use the system without having to log out the previous user and quit his or her applications. Previously on consumer versions of Windows, only one user at a time could be logged in, which was a serious drawback to multi-user activity. However, Fast User Switching requires more system resources than having only a single user logged in at a time and although more than one user can be logged in, only one user can be actively using their account at a time. This feature is not available when the Welcome Screen is turned off, such as when joined to a Windows Server Domain. [8] ( [9] (;en-us;q294737)

Remote Assistance permits support staff to temporarily take over a remote Windows XP computer over a network to resolve issues. [10] ( [11] ( As it can be a hassle for system administrators to personally visit the affected computer, Remote Assistance allows them to diagnose and possibly even repair problems with a computer without ever personally visiting it.

Remote Desktop is available only in Windows XP Professional. It is built on Terminal Services technology (RDP), and is similar to Remote Assistance, but allows remote users to access local resources such as printers. [12] ( Any Terminal Services client, a special "Remote Desktop Connection" client, or a web-based client using an ActiveX control may be used to connect to the Remote Desktop. [13] ( (Remote Desktop clients for earlier versions of Windows have been made available by Microsoft. [14] ( This permits earlier versions of Windows to connect to a Windows XP system running Remote Desktop, but not vice-versa.) There are several resources that users can redirect from the remote server machine to the local client, depending upon the capabilities of the client software used:

  • File System Redirection allows users to use their local files on a remote desktop within the terminal session.
  • Printer Redirection allows users to use their local printer within the terminal session as they would with a locally or network shared printer.
  • Port Redirection allows applications running within the terminal session to access local serial and parallel ports directly.
  • Audio allows users to run an audio program on the remote desktop and have the sound redirected to their local computer.
  • Clipboard can be shared between the remote computer and the local computer.

Windows XP includes technology from Roxio which allows users to directly burn files to a CD through Windows Explorer. Previously, end users had to install CD burning software, such as Nero Burning ROM. Now, burning has been directly integrated into the Windows interface; users burn files to a CD in the same way they write files to a floppy disk or to the hard drive. Windows XP's CD burning support does not do disk to disk copying or disk images. Creation of audio CDs is integrated into Windows Media Player.

Windows XP includes ClearType sub-pixel font anti-aliasing, which makes onscreen fonts smoother and more readable on Liquid Crystal Display (LCD) screens, although this causes a minor performance hit. ClearType has little effect on Cathode Ray Tube (CRT) monitors. However, as portable computers with LCD displays and new LCD monitors have become more common, there is a clear demand for ClearType.

Power management

Before Windows 98, power management was based on the Advanced Power Management architecture. It was of limited use to most users and the feature was easily broken by the addition of hardware devices or software. In Windows 98 ACPI was supported but disabled by default. Windows Me enabled ACPI by default. Windows XP's power management architecture is based on the ACPI standard. It supports multiple levels of sleep states, including critical sleep states when a mobile (or UPS connected) computer is running out of battery power, processor power control (the ability to adjust the speed of the computer's processor on-the-fly to save energy), and the ability of Windows XP to turn off the power to the screen of a laptop when the lid is closed. In addition, it also dims the screen when the laptop has low battery power.

Note that Windows XP still supports APM.

[15] (

Hibernate mode

This involves Windows dumping the entire contents of the RAM to disk and then powering down. On startup it quickly reloads the data. It allows the system to be completely powered off while in hibernate mode. This requires a file the size of the installed RAM to be placed in the system's root directory, using up space even when not in hibernate mode. Hibernate mode is enabled by default and can be disabled in order to recover this disk space.

The Windows hibernation feature conforms to the S4 Sleep State in the ACPI standard.

Standby (Sleep) mode

This involves Windows deactivating all nonessential hardware including the monitor, most fans, hard disks drives, and removable drives. This means that the system reactivates itself very quickly when 'woken up'. It does not allow the system to be powered down. In order to save power without user intervention a system can be configured to go to standby when idle and then hibernate if not re-activated.

The Windows Standby feature conforms to the S1 and S3 Sleep States in the ACPI standard.

Kernel improvements

The Windows XP kernel is not directly comparable to the kernel in Windows 95 derivatives. As an upgrade of the Windows 2000 kernel, the improvements are minor. They include some enhancements to the scalability and performance of the system.

Windows XP includes Simultaneous Multithreading Support, or the ability to utilize the Hyper-Threading feature of newer Intel Pentium 4 processors. Simultaneous Multithreading is a processor's ability to process more than one data thread at a time. Intel has described the effect as being that of having the processing power of two processors for only one.

The ability to boot in 30 seconds was a design goal for Windows XP, and Microsoft's developers made efforts to streamline the system as much as possible; many people have found that without extra services Windows XP can boot from the PC's power on self-test (POST) to the Windows GUI in about 30 seconds. End users can check how long their Windows machine takes to boot by using the now unsupported BootVis program.

Application compatibility

When Windows 95 was released consumers were anxious to maintain compatibility with their applications that had been designed with a 16-bit operating system in mind. The memory constraints of the typical consumer computer ruled out a full 16-bit compatibility layer as Windows NT had done with Windows on Windows (WoW).

As Windows XP merged the consumer and enterprise versions of Windows into one, it folded the user-friendly interface of Windows Me onto the kernel of Windows 2000. A drawback of this is that older software designed for previous versions of Windows may not function. Microsoft addressed this by going to great lengths to improve the WoW with application specific tweaks and shims and providing tools to allow users to try these tweaks and shims on their own applications. [16] (

Another common issue in previous consumer versions of Windows was that users frequently suffered from DLL hell, whereby more than one version of the same Dynamically Linked Library (DLL) was installed on the computer. As software relies on DLLs, using the wrong version could result in non-functional applications, or worse. Windows XP solved this problem by developing a "Side by Side" technology which keeps multiple versions of a DLL in the WinSxS folder and runs them on demand to the appropriate application.

User interface

Windows XP features a new task-based graphical user interface. The Start menu and search capability were redesigned and many visual effects were added, including:

  • A transparent blue selection rectangle in Explorer
  • A watermark-like graphic on folder icons, indicating the type of information stored in the folder.
  • Drop shadows for icon labels on the desktop
  • Task-based sidebars in Explorer windows
  • The ability to group the taskbar buttons of the windows of one application into one button
  • The ability to lock the taskbar and other toolbars to prevent accidental changes
  • The highlighting of recently-added programs on the Start menu

Windows XP analyzes the performance impact of visual effects and uses this to decide whether to enable them, so as to prevent the new functionality from consuming substantial additional processing overhead. These settings can be further customized by users. [17] ( Some effects, such as alpha blending (transparency and fading), are handled entirely by many newer video cards. However, if the video card is not capable of hardware alpha-blending, performance can be substantially hurt and Microsoft recommends the feature should be turned off manually [18] (;EN-US;294770).

Default theme vs Classic theme
Missing image

Missing image


Windows XP adds the ability for Windows to use "Visual Styles" to change the user interface. However, visual styles must be cryptographically signed by Microsoft to run. Luna is the name of the new visual style that ships with Windows XP, and is enabled by default for machines with more than 64 MB of RAM. As Windows XP requires 64 MB of RAM to install, this means that it is enabled for practically all users. Luna refers only to one particular visual style, not to all of the new user interface features of Windows XP as a whole.

The Windows 2000 "classic" interface can be used instead if preferred. Several third party utilities exist that provide hundreds of different visual styles.

Service packs

Microsoft infrequently releases service packs for its Windows operating systems to fix problems and add features.

Service Pack 1

Missing image
Program Access and Defaults Menu added in Service Pack 1

Service Pack 1 (SP1) for Windows XP was released on September 9, 2002. Its most notable new features were USB 2.0 support and a Set Program Access and Defaults utility. For the first time, users could control the default application for activities such as web browsing and instant messaging, as well as hide access to some of Microsoft's bundled programs. This utility was later brought into the older Windows 2000 operating system with its Service Pack 3. Service Pack 1a was later released to remove Microsoft's Java virtual machine as a result of a lawsuit with Sun Microsystems.

LBA-48, which allowed the OS to view and use HDD space above 137 GB, was enabled by default. Native support for Serial ATA was added.

Missing image
Microsoft Security Center added in Service Pack 2
Missing image
Internet Explorer Pop-Up Blocker included with Service Pack 2

Service Pack 2

Service Pack 2 (SP2) was released on August 6, 2004 after several delays, and it focuses on security. Unlike previous service packs, SP2 adds new functionality to Windows XP, including an enhanced firewall, improved Wi-Fi support and a wizard utility, a pop-up ad blocker for Internet Explorer, and Bluetooth support. It also includes a new API to allow third party virus scanners and firewalls to interface with a new security center application, which provides a general overview of security on the system. This helps to suppress spyware and viruses. Other features include enhancements to the Internet Connection Firewall (ICF), now the Windows Firewall (which is also turned on by default), advanced memory protection that takes advantage of the NX instruction that is incorporated into newer processors to stop buffer overflow attacks, removal of raw socket support (which has caused a drop in "zombie" machines: infected computers that can be used remotely to launch denial of service attacks) [19] (, and improvements to e-mail and web browsing [20] ( (a full list of service fixes and modifications for SP2 is available on Microsoft's website (;EN-US;811113)). However, when the service pack was released some programs did stop working, and Microsoft officially listed several of them on its website [21] ( The company AssetMetrix reports that one out of ten computers that upgraded to SP2 had severe compatibility problems with their applications. [22] ( [23] (

SP2 also includes major updates to Windows XP Tablet PC Edition and Windows XP Media Center Edition, and also supports 24 new languages from every continent. [24] (

While well received in general, Service Pack 2 is not without its critics. Thomas Greene from The Register claimed that SP2 was merely a placebo of sorts in terms of features, fixes, and security updates:

"While we found that there are indeed a few minor improvements worthy of acknowledgment, in particular, some rather low-level improvements that don't show to the admin or user, overall, SP2 did little to improve our system's practical security, leaving too many services and networking components enabled, bungling permissions, leaving IE and OE vulnerable to malicious scripts, and installing a packet filter that lacks a capacity for egress filtering." [25] (

Service Pack 3 (pending)

In February of 2005, Mike Nash, an executive at Microsoft was quoted as saying there will be a Service Pack 3 for Windows XP. Little is known about it except that it may include a new version of Internet Explorer which enables tabbed browsing and will probably include security updates. [26] (

Common criticisms of Windows XP

Security issues

Security concerns have long been an issue with Microsoft products. Windows XP has been criticized for its susceptibility to buffer overflows, malware, viruses, and worms.

Many attacks against Windows XP systems come in the form of e-mail Trojan horses which are sent by worms. A user who opens the file attachment(s) can unknowingly infect his or her own computer, which then e-mails the worm to more people. Notable worms of this sort which have infected Windows XP systems include Mydoom and Bagle.

In August 2003 the Blaster worm, which became one of the most well known Windows worms, exploited a vulnerability which is present in every unpatched installation of Windows XP and can compromise a system even without user action. Even security-conscious users can have trouble with Blaster, since it can infect a computer with a newly installed copy of Windows XP before the user has time to download security fixes [27] (

Windows XP was also vulnerable to the Sasser worm, spread by using a buffer overflow in a remote service present on every installation. In May 2004, Sasser quickly spread through computers running Windows XP and Windows 2000.

No such worms have been seen since Service Pack 2 closed the loopholes these worms needed to spread [28] (

In January 2005 Microsoft launched the beta version of their Anti-Spyware system, a free download, which removes spyware from user's computers [29] ( Spyware and adware are a continuing problem on Windows XP and other versions of Windows. Spyware is also a concern for Microsoft with regards to service pack updates; Barry Goff, a group product manager at Microsoft, said some spyware could cause computers to freeze up upon installation of Service Pack 2 [30] (

This security issue is compounded by the fact that users, by default, get an administrator account that gives them full access to the system. This means that any damage that is done to a compromised machine is not limited if the administrator's account is cracked into. Nicholas Petreley for The Register notes that "Windows XP was the first version of Windows to reflect a serious effort to isolate users from the system, so that users each have their own private files and limited system privileges." [31] (, however Rob Pegoraro, for the Washington Post noted that "XP Home's "limited account," the only other option, doesn't even let you adjust a PC's clock." [32] ( XP Home also lacks the ability to administer security policies (secpol.msc) and denies access to the Local Users and Groups utility (lusrmgr.msc).

Windows XP offers some useful security benefits, such as Windows Update, which can be set to install security patches automatically, and a built-in firewall. SP2 turns on the firewall by default, and also adds increased memory protection to let the operating system take advantage of new No eXecute technology built into CPUs such as the AMD64. This allows Windows XP to prevent code from being executed on areas of memory flagged with an NX bit and stops buffer overflow exploits from running arbitrary code.

Windows, with its large market share, has traditionally been a tempting target for virus creators. Security holes often aren't visible until they are exploited, making preemptive action difficult. Microsoft executives have stated that the release of patches to fix security holes is often what causes the spread of exploits against those very same holes, as crackers figured out what problems the patches fixed then launch attacks against unpatched systems.

Perhaps the greatest threats against Windows security are the actions of Windows users themselves. There is little defense against a user opening an e-mail attachment without realizing that it is malicious (the default setting of Windows XP to hide file extensions doesn't help in this regard), or failing to keep reasonably current on Windows Update patches.

Product activation

While product activation and licensing servers are common for business and industrial software (especially software sold on a per-user basis for large sums of money), Windows XP gave many casual computer users their first introduction to it. The system was introduced by Microsoft to curb illegal distribution of Windows XP [33] ( Activation requires the computer or the user to activate with Microsoft within a certain amount of time in order to continue using the operating system. If the user's computer system ever changes — for example, if two or more relevant components (see list below) of the computer itself are upgraded — Windows may refuse to run until the user reactivates with Microsoft.

Privacy fears were raised about the nature of the data transmitted to Microsoft. Microsoft then released details about the nature of the information transmitted [34] ( It includes a cryptographic hash of the following ten values:

  • Display adapter name
  • SCSI adapter name
  • IDE adapter name
  • Network adapter MAC address
  • RAM amount (as a range, e.g. 0–64 MB, 64–128 MB, etc.)
  • Processor type
  • Processor serial number (if applicable)
  • Hard drive device
  • Hard drive volume serial number
  • CD-ROM/ CD-RW/ DVD-ROM identification

This information is used to seed the generation of a number which, along with the CD Key and country of installation, is transmitted to Microsoft. According to Microsoft, no specific details about the hardware are transmitted.

Entering a specially crafted Volume License Key (VLK) into a copy of Windows XP Professional disables Windows Product Activation entirely. Copies of Windows XP Professional with WPA disabled through the use of a VLK are commonly referred to as "Windows XP Corporate Edition". A VLK can be entered during installation of Windows or afterwards, by invoking the Windows Product Activation Wizard. According to Microsoft, 90% of pirated installations of Windows XP use VLKs to circumvent WPA. The most famous VLK is one beginning with FCKGW, which was released with the first pirated copies of the final version of Windows XP.

This provided no protection as key changers and keygens were soon available on the Internet.

User interface and performance

Critics have claimed that the default Windows XP user interface (Luna) adds visual clutter and wastes screen space while offering no new functionality and running more slowly. Supporters of the new interface praise its task-oriented nature and the automatic grouping of related windows on the taskbar to reduce clutter, and point out that the higher system requirements of Windows XP allow it to easily handle the increased processor demand; with a small amount of tweaking, it is possible to return to the Windows 2000 look, which is faster, but many consider this less visually attractive.

CNET's web site lists hundreds of positive and negative reviews of Windows XP Home [35] ( and Professional [36] ( from users. David Coursey, Executive Editor of ZDNet's AnchorDesk [37] (, and Paul Thurrott, who runs SuperSite for Windows [38] ( have both written positive reviews of the operating system.

Integration of operating system features

In light of the United States v. Microsoft case which resulted in Microsoft being convicted for illegally abusing its operating system monopoly to overwhelm competition in other markets, Windows XP has drawn fire for integrating user applications such as Windows Media Player and MSN Messenger into the operating system, as well as for its close ties to the Microsoft Passport Network service.

In 2001, ProComp claimed that the bundling and distribution of Windows Media Player in Windows XP was a continuance of Microsoft's anticompetitive behavior [39] (, and that the integration of Passport into Windows XP was a further example of Microsoft attempting to gain a monopoly in web services [40] ( Both of these claims were rebutted by the Association for Competitive Technology (ACT) and the Computing Technology Industry Association (CompTIA) [41] ( [42] (,1551,44170,00.html). ProComp is a group including several of Microsoft's rivals, including Oracle, Sun, and Netscape. ACT and CompTIA are both partially funded by Microsoft. The battle being fought by fronts for each side was the subject of a heated exchange between Oracle's Larry Ellison and Microsoft's Bill Gates[43] (

Microsoft responded on its "Freedom to Innovate" web site (, pointing out that in earlier versions of Windows, Microsoft had integrated tools such as disk defragmenters, graphical file managers, and TCP/IP stacks, and there had been no protest that Microsoft was being anti-competitive. Microsoft asserted that these tools had moved from special to general usage and therefore belonged in its operating system.

To avoid the possibility of an injunction which might have delayed the release of Windows XP, Microsoft changed its licensing terms to allow PC manufacturers to hide access to Internet Explorer (but not remove it). Competitors dismissed this as a trivial gesture [44] ( Later, Microsoft released a utility as part of the SP1 which allows icons and other links to bundled software such as Internet Explorer, Windows Media Player, and MSN Messenger to be removed. The components themselves remain in the system; Microsoft maintains that they are necessary for key Windows functionality (such as the HTML Help system and Windows desktop), and that removing them completely may result in unwanted consequences. One critic, Shane Brooks, has argued that Internet Explorer could be removed without adverse effects, as demonstrated with his product XPlite [45] ( Dino Nuhagic created his nLite software to remove many components from XP prior to installation of the product [46] (

In addition, the first release of Windows XP, the "Buy Music Online" feature always used Microsoft's Internet Explorer rather than any other web browser that the user may have set as his/her default. Whether this flaw was intentional or simply an oversight is unclear. Under pressure from the United States Department of Justice, Microsoft released a patch in early 2004, which corrected the problem [47] (

Copying restrictions

Microsoft Windows XP service packs are designed so that they will not install on computers running installations of Windows XP that use product keys known to be widely used in unauthorized installations. These product keys are unique to each boxed (or bundled) copy of Windows XP and are included with the product documentation, but a small number of product keys have been posted on the Internet and are responsible for a large number of unauthorized installations. The service packs contain a list of these keys and will not update copies of Windows XP which use them.

Microsoft developed a new key verification engine (internally known as "Soup Nazi") for Windows XP Service Pack 2 that could detect illicit keys, even those that had never been used before. After an outcry from security consultants who feared that denying security updates to illegal installations of Windows XP would have wide-ranging consequences even for legal owners, Microsoft elected to disable the new key verification engine. Service Pack 2 only checks for the same small list of commonly used keys as Service Pack 1. This means that while Service Pack 2 will not install on copies of Windows XP which use the older set of copied keys, those who use keys which have been posted more recently may be able to update their systems.

See also

History of Microsoft Windows
Windows: 1.0 | 2.0 | 3.x | NT | 95 | 98 | Me | 2000 | XP | Server 2003 | Server 2003 R2 | CE | Mobile | Longhorn | Blackcomb



  • Art and Cultures
    • Art (
    • Architecture (
    • Cultures (
    • Music (
    • Musical Instruments (
  • Biographies (
  • Clipart (
  • Geography (
    • Countries of the World (
    • Maps (
    • Flags (
    • Continents (
  • History (
    • Ancient Civilizations (
    • Industrial Revolution (
    • Middle Ages (
    • Prehistory (
    • Renaissance (
    • Timelines (
    • United States (
    • Wars (
    • World History (
  • Human Body (
  • Mathematics (
  • Reference (
  • Science (
    • Animals (
    • Aviation (
    • Dinosaurs (
    • Earth (
    • Inventions (
    • Physical Science (
    • Plants (
    • Scientists (
  • Social Studies (
    • Anthropology (
    • Economics (
    • Government (
    • Religion (
    • Holidays (
  • Space and Astronomy
    • Solar System (
    • Planets (
  • Sports (
  • Timelines (
  • Weather (
  • US States (


  • Home Page (
  • Contact Us (

  • Clip Art (
Personal tools