Features new to Windows XP
As the next version of Windows NT after Windows 2000, as well as the successor to Windows Me, Windows XP introduced many new features but it also removed some others.
User interface and appearance
Graphics
With the introduction of Windows XP, the C++ based software-only GDI+ subsystem was introduced to replace certain GDI functions. GDI+ adds anti-aliased 2D graphics, textures, floating point coordinates, gradient shading, more complex path management, bicubic filtering, intrinsic support for modern graphics-file formats like JPEG and PNG, and support for composition of affine transformations in the 2D view pipeline. GDI+ uses RGBA values to represent color. Use of these features is apparent in Windows XP's user interface, and several of its applications such as Microsoft Paint, Windows Picture and Fax Viewer, , My Pictures Slideshow screensaver, and their presence in the basic graphics layer greatly simplifies implementations of vector-graphics systems such as Flash or SVG. The GDI+ dynamic library can be shipped with an application and used under older versions of Windows. The total number of GDI handles per session is also raised in Windows XP from 16,384 to 65,536.Windows XP shipped with DirectX 8.1, which brings major new features to DirectX Graphics besides DirectX Audio, DirectPlay, DirectInput, and DirectShow. Direct3D introduced programmability in the form of vertex and pixel shaders, enabling developers to write code without worrying about superfluous hardware state, fog, bump mapping, and texture mapping. DirectX 9 was released in 2003, which also saw major revisions to Direct3D, DirectSound, DirectMusic, and DirectShow. Direct3D 9 added a new version of the High-Level Shader Language, support for floating-point texture formats, Multiple Render Targets, and texture lookups in the vertex shader. Windows XP can be upgraded to DirectX 9.0c.
ClearType
Windows XP includes ClearType subpixel rendering, which makes onscreen fonts smoother and more readable on liquid-crystal display screens. Although ClearType affects CRT monitors, its primary use is for LCD/TFT-based displays. ClearType in Windows XP currently supports the RGB and BGR subpixel structures. There are other parameters, such as contrast, that can be set via a ClearType Tuner power toy that Microsoft makes available as a free download from its Typography website.Start menu
With Windows XP, the Start button has an updated appearance and is larger, making it faster to mouse over to it and click it. To help the user access a wider range of common destinations more easily from a single location, the Start menu was expanded to two columns; the left column focuses on the user's installed applications, while the right column provides access to the user's documents, and system links which were previously located on the desktop. Links to the My Documents, My Pictures, and other special folders are brought to the fore. The My Computer and My Network Places icons were also moved off the Desktop and into the Start menu, making it easier to access these icons while a number of applications are open and so that the desktop remains clean. Moreover, these links can be configured to expand as a cascading menu. Frequently used programs are automatically displayed in the left column, newly installed programs are highlighted, and the user may opt to "pin" programs to the start menu so that they are always accessible without having to navigate through the Programs folders. The default web browser and default email program are pinned to the Start menu. The Start menu is fully customizable; links can be added or removed, the number of frequently used programs to display can be set. The All Programs menu expands like the classic Start menu to utilize the entire screen but can be set to scroll programs. The user's name and the user's account picture are also shown on the Start menu.Taskbar
The taskbar buttons for running applications and Quick Launch have also been updated for Fitt's law. Locking the taskbar not only prevents it from being accidentally resized or moved but elements such as Quick launch and other DeskBands are also locked from being accidentally moved. The Taskbar grouping feature combines multiple buttons of the same application into a single button, which when clicked, pops up a menu listing all the grouped windows and their number. Advanced taskbar grouping options can be configured from the registry. The user can choose to always show, always hide or hide some or all notification area icons if inactive for some time. A button allows the user to reveal all the icons. The Taskbar, if set to a thicker height also displays the day and date in the notification area.Windows Explorer
There are significant changes made to Windows Explorer in Windows XP, both visually and functionally. Microsoft focused especially on making Windows Explorer more discoverable and task-based, as well as adding a number of features to reflect the growing use of a computer as a "digital hub".Task pane
The task pane is displayed on the left side of the window instead of the traditional folder tree view when the navigation pane is turned off. It presents the user with a list of common actions and destinations that are relevant to the current directory or file selected. For instance, when in a directory containing mostly pictures, a set of "Picture tasks" is shown, offering the options to display these pictures as a slide show, to print them, or to go online to order prints. Conversely, a folder containing music files would offer options to play those files in a media player, or to go online to purchase music.Every folder also has "File and Folder Tasks", offering options to create new folders, share a folder on the local network, publish files or folders to a web site using the Web Publishing Wizard, and other common tasks like copying, renaming, moving, and deleting files or folders. File types that have identified themselves as being printable also have an option listed to print the file.
Underneath "File and Folder Tasks" is "Other Places", which always lists the parent folder of the folder being viewed and includes additional links to other common locations such as "My Computer", "Control Panel", and "My Documents" or previously navigated locations. These change depending on what folder the user was in.
Underneath "Other Places" is a "Details" area which gives additional information when a file or folder is selected – typically the file type, file size and date modified, but depending on the file type, author, image dimensions, attributes, or other details. If the file type has a Thumbnail image handler installed, its preview also appears in the "Details" task pane. For music files, it might show the artist, album title, and the length of the song. The same information is also shown horizontally on the status bar.
Navigation pane
The "Folders" button on the Windows Explorer toolbar toggles between the traditional navigation pane containing the tree view of folders, and the task pane. Users can also close the navigation pane by clicking the Close button in its right corner as well as turn off the task pane from Folder Options.The navigation pane has been enhanced in Windows XP to support "simple folder view" which when turned on hides the dotted lines that connect folders and subfolders and makes folders browsable with single click while still keeping double clicking on in the right pane. Single clicking in simple folder view auto expands the folder and clicking another folder automatically expands that folder and collapses the previous one.
Grouping and sorting
Windows XP introduced a large number of metadata properties which are shown as columns in the "Details" view of Explorer, in the new Tiles view in Explorer, on the Summary tab in a file's properties, in a file's tooltip and on the Explorer status bar when a single file is selected. Users also gain the ability to sort by any property which is turned on in "Details" view. Developers can write column handler shell extensions to further define their own properties by which files can be sorted. The column by which items are sorted is highlighted. Sorting files and folders can be in Ascending order or Descending order in all views, not just Details view. To reverse the order, the user simply can perform the sort by the same property again. The sort order has also been made more intuitive compared to the one in Windows 2000. For file names containing numbers Windows Explorer now tries to sort based on numerical value rather than just comparing each number digit by digit for every character position in the file name. For instance, files containing "1", "2".."10" will be intuitively sorted with "10" appearing after "9" instead of appearing between "1" and "2".The right pane of Windows Explorer has a "Show in Groups" feature which allows Explorer to separate its contents by headings based on any field which is used to sort the items. Items can thus be grouped by any detail which is turned on. "Show in Groups" is available in Thumbnails, Tiles, Icons and Details views.
Search
Microsoft introduced animated "Search Companions" in an attempt to make searching more engaging and friendly; the default character is a puppy named Rover, with three other characters also available. These search companions powered by Microsoft Agent technology, bear a great deal of similarity to Microsoft Office's Office Assistants, even incorporating "tricks" and sound effects. If the user wishes, they can also turn off the animated character entirely.The search capability itself is fairly similar to Windows Me and Windows 2000, with some important additions. The Indexing Service can extract Exif properties, as well as some metadata for ASF, WMV and MP3 files under Windows XP via the IPropertyStorage interface using built-in Null Filter. Search can also be instructed to search only files that are categorically "Documents" or "Pictures, music and video" ; this feature is noteworthy largely because of how Windows determines what types of files can be classified under these categories. Another important addition is that the "Look in" field accepts and expands environment variables for abbreviated entry of long paths. Also, users can configure whether or not Windows XP searches for system and/or hidden files and folders. Using Tweak UI, the search user interface can be restored to the one used by Windows 2000.