The Windows XP 64-Bit Edition was designed specifically for Itanium-based workstations, and is incompatible with most other 64-bit processors. This edition was discontinued in early 2005, after HP, the last distributor of Itanium-based workstations, stopped selling Itanium systems marketed as 'workstations'. However, Itanium support continues in the server editions of Windows. AMD 64-bit processors, namely x86-compatible 64-bit ones, may be used on Windows XP Professional x64 Edition, which was based on Windows Server 2003. This version of Windows XP supports AMD's Opteron and Athlon 64 chips, as well as Intel's chips with EM64T.
Microsoft had previously supported other microprocessors with earlier versions of the Windows NT operating system line (including two 64-bit lines, the DEC Alpha and the MIPS R4000, although Windows NT used them as 32-bit processors). The files necessary for all of the architectures were included on the same installation CD and did not require the purchase of separate versions.
Windows XP Media Center Edition
The Windows XP Media Center Edition was made for special Media center PCs. Originally, it was only available bundled with one of these computers, and could not be purchased separately. In 2003 the Media Center Edition was updated as "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.
Windows XP Tablet PC Edition
Internet Explorer 6 running on a Tablet PC.
For specially designed notebook/laptop computers called tablet PCs, Microsoft designed the Windows XP Tablet PC Edition. The Tablet PC Edition is compatible with a pen-sensitive screen, supporting handwritten notes and portrait-oriented screens. It cannot be purchased separately from a Tablet PC.
Windows XP Embedded
Another unique edition is 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 Fundamentals for Legacy PCs
In July 2006, Microsoft introduced a "thin-client" version of Windows XP called Windows Fundamentals for Legacy PCs, which targets older machines (as early as the original Pentium). It will only be available to Software Assurance customers, who would like to upgrade to Windows XP to take advantage of its security and management capabilities, but can't afford to purchase new hardware. Applications will typically be run on a remote server using Remote Desktop.
Windows XP Starter Edition
Windows XP Starter Edition is a lower-cost version of Windows XP available in Thailand, Turkey, Malaysia, Indonesia, Russia, India, Brazil, Argentina, Chile, Mexico, Ecuador, Uruguay and Venezuela. It is similar to Windows XP Home, but is limited to low-end hardware, can only run 3 programs at a time, and has some other features either removed or disabled by default.
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 possibly the spread of GNU/Linux-based systems in Asia and South America.
Specializations
To appeal to foreign markets whose consumers may not be computer literate, the Starter Edition includes additional specializations not found in the Home Edition such as localized help features for those who may not speak English, a country-specific computer wallpaperFast user switching, which allows a user to save the current state and open applications of their desktop and allow another user to log on without losing that information; *The ClearType font rendering mechanism, which is designed to improve text readability on Liquid Crystal Display (LCD) and similar monitors; *The Remote Desktop functionality, which allows users to connect to a computer running Windows XP from across a network or the Internet and access their applications, files, printers, and devices; and *Support for most DSL modems and wireless network connections, as well as networking over FireWire.
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 translucent 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 ("common tasks") *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 *Shadows under menus (Windows 2000 had shadows under mouse pointers, but not menus)
Windows XP analyzes the performance impact of visual effects and uses this to determine whether to enable them, so as to prevent the new functionality from consuming excessive additional processing overhead. Users can further customize these settings. (Click on the Windows XP link on the left hand list for a pop-up with more details.).
Microsoft occasionally releases service packs for its Windows operating systems to fix problems and add features.
Service Pack 1
Program Access and Defaults Menu were added in Service Pack 1.
Microsoft Security Center was added in Service Pack 2.
Internet Explorer Pop-Up Blocker was also included with Service Pack 2.
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.
Support for Windows XP Service Pack 1 is scheduled to end on October 10, 2006.
Service Pack 2
Service Pack 2 (SP2) was released on August 6, 2004 after several delays, with a special emphasis on security. Unlike previous service packs, SP2 adds new functionality to Windows XP, including an enhanced firewall, improved Wi-Fi support with 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), improvements to e-mail and web browsing, and Windows Movie Maker 2. Movie Maker 2 has a new interface and more transitions, video effects and options. A full list of service fixes and modifications in SP2 is available on Microsoft's website
Security issues
Windows XP has been criticized for its susceptibility to malware, viruses, trojan horses and worms. Security issues are compounded by the fact that users, by default, receive an administrator account that provides unrestricted access to the underpinnings of the system. If the administrator's account is broken into, there is no limit to the control that can be asserted over the compromised PC.
Windows, with its large market share, has historically been a tempting target for virus creators. Security holes are often invisible until they are exploited, making preemptive action difficult. Microsoft has 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, and then launch attacks against unpatched systems.
In an effort to slow down the rate at which malicious programs can spread to uninfected computers, Service Pack 2 lowered the limit on outgoing TCP/IP connection attempts from 65,535 to 10. There can be no more than this many incomplete outgoing connections being attempted at any one time; additional connection attempts will be queued. This limit can adversely affect legitimate software such as peer-to-peer applications. The "tcpip.sys" system file can be patched to raise the limit to its former value.
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 unauthorized distribution of Windows XP.
