Windows Search is a standard component of Windows Vista enabled by default and an add-in for Microsoft Windows XP which allows instant search capabilities for most common file and data types such as e-mail, contacts, calendar appointments, documents, photos, multimedia, and other formats extended by third-parties. These capabilities enable consumers and Information Workers to more efficiently find, manage, and organize the increasing amount of data common in home and enterprise environments.
The content indexed is based on the file and data types supported through add-ins included with Windows Search and the default inclusion and exclusion rules for folders in the file system. For example, the filters included in Window Search support over 200 common types of data including support for Microsoft Office documents, Microsoft Outlook e-mail (in conjunction with the MAPI protocol handler), plain-text files, HTML, and many more. For a full list of file types natively supported, refer to What Is Included in the Index.
History of Windows Search
Windows Search replaces the legacy Indexing Service from previous versions of Windows with enhancements to performance, usability, and extensibility. The development platform supports new requirements that produce a more secure and stable system. While the new querying platform is not compatible with Microsoft Windows Desktop Search (WDS) 2.x, filters and protocol handlers written for previous versions of WDS can be updated to work with Windows Search. Windows Search also supports a new property system. See Extending the Index for more information on filters, property handlers, and protocol handlers.
Windows Search is built into Windows Vista and is available as a redistributable update to WDS 2.x, supporting the following operating systems:
- 32-bit versions of Windows XP with Service Pack 2 (SP2)
- All x64-based versions of Windows XP
- Windows Server 2003 with Service Pack 1 (SP1) and later
- All x64-based versions of Windows Server 2003
Systems running these operating systems must have Windows Search installed to run applications written for Windows Search. For more information and to download, refer to KB article 917013.
Windows Search Components
There are three areas that comprise Windows Search: a Windows Search service, user interface, and development platform.
Windows Search Service
The main component of Windows Search is the indexer process which is implemented as a Windows service running in the LocalSystem account. The process is always running for all users (even if no user is logged in), enabling Windows Search to maintain one index shared among all users with security restrictions on content access and to process remote queries from client machines on the network.
The Search service is designed to protect the user experience and system performance when indexing. A number of conditions cause the service to throttle back or pause indexing:
- High CPU usage by non-search-related processes
- High system I/O rate including file reads and writes, page file and file cache I/O, and mapped file I/O
- Low memory availability
- Low battery life
- Low disk space on the drive storing the index
User Interface
Windows Vista integrates search into all Windows Explorer windows for instant access to search. This enables users to quickly search for files and items by file name, properties, and full-text contents. Results can also be filtered further to refine the search.
- Instant search box in every window allows instant filtering of all items currently in view. Instant search boxes appear in the Start menu to search for programs or files and the top right corner of all Windows Explorer windows to filter the results shown. Instant search is also integrated into some Windows applications, such as Windows Media Player, to find related files.
- Enhanced column headers in Windows Explorer views for sorting and grouping documents in different ways. For example, files can be sorted according to name, date modified, type, size and tag. Documents can also be grouped according to any of these properties and each group can be filtered (hidden or displayed) as desired.
- Documents can be stacked according to name, date modified, type, size and tags. Stacks include all documents having the specified property and located within any subfolder of the selected folder.
- Documents can also be tagged with keywords to group them by custom criteria defined by the user. Tags are metadata assigned by the user or applications to make it easier to find files based on keywords that may not be in the item name or contents. For example, a set of pictures may be tagged as "Arizona Vacation 2004" to quickly retrieve later by searching for any of the included words.
- Searches can be saved to be retrieved later by clicking the Save Search button in the search pane in Windows Explorer. The results will be dynamically repopulated based on its criteria when the saved search is opened.
- Preview handlers and thumbnail handlers allow documents to be previewed in Windows Explorer without having to open the application which created them.
Development Platform
Third-part developers can create applications that consume the data in the index through programmatic queries, and can extend the data in the index for custom file and item types to be indexed by Windows Search.
For more information, refer to Development Platform Overview.
Windows Search MSDN Forums
There are two Windows Search MSDN Forums, community-supported question and discussion message boards, that developers might find helpful. One is in the Vista forum category and the other is in the Windows Search Technologies category: