Overview of the features newly introduced in the Microsoft Windows 7 operating system
Some of the new features included in Windows 7 are advancements in touch, speech and handwriting recognition, support for virtual hard disks, support for additional file formats, improved performance on multi-core processors, improved boot performance, and kernel improvements.
Shell and user interface.
Windows 7 retains the Windows Aero graphical user interface and visual style introduced in its predecessor, Windows Vista, but many areas have seen enhancements. Unlike Windows Vista, window borders and the taskbar do not turn opaque when a window is maximized while Windows Aero is active; instead, they remain translucent.
Desktop.
Themes.
Support for themes has been extended in Windows 7. In addition to providing options to customize colors of window chrome and other aspects of the interface including the desktop background, icons, mouse cursors, and sound schemes, the operating system also includes a native desktop slideshow feature. A new theme pack extension has been introduced, codice_1, which is essentially a collection of cabinet files that consist of theme resources including background images, color preferences, desktop icons, mouse cursors, and sound schemes. The new theme extension simplifies sharing of themes and can also display desktop wallpapers via RSS feeds provided by the Windows RSS Platform. Microsoft provides additional themes for free through its website.
The default theme in Windows 7 consists of a single desktop wallpaper named "Harmony" and the default desktop icons, mouse cursors, and sound scheme introduced in Windows Vista; however, none of the desktop backgrounds included with Windows Vista are present in Windows 7. New themes include "Architecture", "Characters", "Landscapes", "Nature", and "Scenes", and an additional country-specific theme that is determined based on the defined locale when the operating system is installed; although only the theme for a user's home country is displayed within the user interface, the files for all of these other country-specific themes are included in the operating system. All themes included in Windows 7—excluding the default theme—include six wallpaper images. A number of new sound schemes (each associated with an included theme) have also been introduced: "Afternoon", "Calligraphy", "Characters", "Cityscape", "Delta", "Festival", "Garden", "Heritage", "Landscape", "Quirky", "Raga", "Savana", and "Sonata". Themes may introduce their own custom sounds, which can be used with others themes as well.
Desktop Slideshow.
Windows 7 introduces a desktop slideshow feature that periodically changes the desktop wallpaper based on a user-defined interval; the change is accompanied by a smooth fade transition with a duration that can be customized via the Windows Registry. The desktop slideshow feature supports local images and images obtained via RSS.
Gadgets.
With Windows Vista, Microsoft introduced the Windows Sidebar to host Microsoft Gadgets that displayed details such as feeds and sports scores; the gadgets could optionally be placed on the Windows desktop. With Windows 7, gadgets can still be placed on the Windows desktop, but the Windows Sidebar itself has been removed, and the platform has been renamed as "Windows Desktop Gadgets". Gadgets are more closely integrated with Windows Explorer, but the gadgets themselves continue to operate in a single codice_2 process (unlike in Windows Vista where gadgets could operate in multiple codice_2 processes). New features for gadgets include:
Windows 7 also introduces a single new gadget, one for Windows Media Center that displays links to the various sections (e.g., "Pictures + Videos") of its interface.
Branding and customization.
For original equipment manufacturers and enterprises, Windows 7 natively supports the ability to customize the wallpaper that is displayed during user login. Because the settings to change the wallpaper are available via the Windows Registry, users can also customize this wallpaper. Options to customize the appearance of interface lighting and shadows are also available.
Windows Explorer.
Libraries.
Windows Explorer in Windows 7 supports file libraries that aggregate content from various locations – including shared folders on networked systems if the shared folder has been indexed by the host system – and present them in a unified view. The libraries hide the actual location the file is stored in. Searching in a library automatically federates the query to the remote systems, in addition to searching on the local system, so that files on the remote systems are also searched. Unlike search folders, Libraries are backed by a physical location which allows files to be saved in the Libraries. Such files are transparently saved in the backing physical folder. The default save location for a library may be configured by the user, as can the default view layout for each library. Libraries are generally stored in the "Libraries" special folder, which allows them to be displayed on the Navigation Pane.
By default, a new user account in Windows 7 contains four libraries for different file types: Documents, Music, Pictures, and Videos. They are configured to include the user's profile folders for these respective file types, as well as the computer's corresponding Public folders. The Public folder also contains a hidden Recorded TV library that appears in the Windows Explorer sidepane when TV is set up in Media Center for the first time.
In addition to aggregating multiple storage locations, Libraries enable Arrangement Views and Search Filter Suggestions. Arrangement Views allow you to pivot your view of the library's contents based on metadata. For example, selecting the "By Month" view in the Pictures library will display photos in stacks, where each stack represents a month of photos based on the date they were taken. In the Music library, the "By Artist" view will display stacks of albums from the artists in your collection, and browsing into an artist stack will then display the relevant albums.
Search Filter Suggestions are a new feature of the Windows 7 Explorer's search box. When the user clicks in the search box, a menu shows up below it showing recent searches as well as suggested Advanced Query Syntax filters that the user can type. When one is selected (or typed in manually), the menu will update to show the possible values to filter by for that property, and this list is based on the current location and other parts of the query already typed. For example, selecting the "tags" filter or typing "tags:" into the search box will display the list of possible tag values which will return search results.
Arrangement Views and Search Filter Suggestions are database-backed features which require that all locations in the Library be indexed by the Windows Search service. Local disk locations must be indexed by the local indexer, and Windows Explorer will automatically add locations to the indexing scope when they are included in a library. Remote locations can be indexed by the indexer on another Windows 7 machine, on a Windows machine running Windows Search 4 (such as Windows Vista or Windows Home Server), or on another device that implements the MS-WSP remote query protocol.
Federated search.
Windows Explorer also supports federating search to external data sources, such as custom databases or web services, that are exposed over the web and described via an OpenSearch definition. The federated location description (called a "Search Connector") is provided as an codice_4 file. Once installed, the data source becomes queryable directly from Windows Explorer. Windows Explorer features, such as previews and thumbnails, work with the results of a federated search as well.
Miscellaneous Shell enhancements.
Windows Explorer has received numerous minor enhancements that improve its overall functionality. The address bar and search box can be resized. The Command Bar features the "New Folder" command and a visible interface option to enable the Preview Pane (both were previously in the "Organize" option in Windows Vista). A new "Content" icon view mode is added, which shows metadata and thumbnails. The "List" icon view mode provides more space between items than in Windows Vista. Storage capacity indicators for hard disks introduced in Windows Vista are now also shown for removable storage devices. File types for which new iFilters or Property Handlers are installed are reindexed by Windows Search by default. 
The Navigation Pane includes a new "Favorites" location, which serves as the replacement for the "Favorite Links" functionality of the interface in Windows Vista, and newly created Saved Searches are automatically pinned to this location.
There is a new "Share With" button on the Command Bar that allows users to share the currently viewed folder or currently selected item with people in a homegroup with either read permissions or with both read and write permissions, or with specific people, which opens the Sharing Wizard introduced in Windows Vista; a new "Nobody" sharing option prevents the selected folder or item from being shared, and all items that are excluded in this manner feature a new padlock overlay icon.
Previously, adding submenus to Shell context menus or customizing the context menu's behavior for a certain folder was only possible by installing a form of plug-in known as Shell extensions. In Windows 7, however, users can edit the Windows Registry or configuration files. Additionally, a new Shell API was introduced designed to simplify the writing of context menu shell extensions by software developers.
Windows 7 includes native support for burning ISO files. The functionality is available when a user selects the "Burn disc image" option within the context menu of an ISO file (support for disc image verification is also included). In previous versions of Windows, users were required to install third-party software to burn ISO images.
Start menu.
The start button now has a fade-in highlight effect when the user hovers over it with the mouse cursor. The right column of the Start menu is now prominently the Aero Glass color; in Windows Vista, it was predominantly black regardless of the color in use.
Windows 7's Start menu retains the two-column layout of its predecessors, with several functional changes:
Group Policy settings for Windows Explorer provide the ability for administrators of an Active Directory domain to add up to five Internet Web sites and five additional "search connectors" to the Search Results view in the Start menu. The links, which appear at the bottom of the pane, allow the search to be executed again on the selected web site or search connector. Microsoft suggests that network administrators could use this feature to enable searching of corporate Intranets or an internal SharePoint server.
Taskbar.
The Windows Taskbar has seen its most significant revision since its introduction in Windows 95 and combines the previous Quick Launch functionality with open application window icons. The taskbar is now rendered as an Aero Glass element whose color can be changed via the Personalization Control Panel. It is 10 pixels taller than in Windows Vista to accommodate touch screen input and a new larger default icon size (although a smaller taskbar size is available), as well as maintain proportion to newer high resolution monitor modes. Running applications are denoted by a border frame around the icon. Within this border, a color effect (dependent on the predominant color of the icon) that follows the mouse cursor also indicates the opened status of the application. The glass taskbar is more translucent than in Windows Vista. Taskbar buttons show icons by default, not application titles, unless they are set to 'not combine', or 'combine when taskbar is full.' In this case, only icons are shown when the application is not running. Programs running or pinned on the taskbar can be rearranged. Items in the notification area can also be rearranged.
Pinned applications.
The Windows 7 taskbar is more application-oriented than window-oriented, and therefore doesn't show window titles (these are shown when an application icon is clicked or hovered over). Applications can now be pinned to the taskbar allowing the user instant access to the applications they commonly use. There are a few ways to pin applications to the taskbar. Icons can be dragged and dropped onto the taskbar, or the application's icon can be right-clicked to pin it to the taskbar. The Quick Launch toolbar has been removed from the default configuration, but can be manually added back.
Thumbnail previews.
Thumbnail previews which were introduced in Windows Vista have been expanded to not only preview the windows opened by the application in a small-sized thumbnail view, but to also interact with them. The user can close any window opened by clicking the X on the corresponding thumbnail preview. The name of the window is also shown in the thumbnail preview. A "peek" at the window is obtained by hovering over the thumbnail preview. Peeking brings up only the window of the thumbnail preview over which the mouse cursor hovers, and turns any other windows on