Searches are performed not only on file names, but also on the contents of the file (provided a proper handler for the file type is installed such as a PDF reader) as well as the keywords, comments and all other forms of metadata that Windows Search recognizes. Once a file's contents have been added to this index, Windows Search is able to use the index to search results more rapidly than it would take to search through all the files on the computer. The time required for the initial creation of this index depends on the amount and type of data to be indexed, and can take up to several hours, but this is a one-time event. Windows Search creates a locally stored index of files and non-file items stored on a computer. Microsoft began development of Windows Search after the postponement of WinFS it introduces features originally touted as benefits of that platform, such as content indexing, incremental searching, and property stacking. Windows Search is the successor of the Indexing Service, a remnant of the Object File System feature of the Cairo project which never materialized. There have been several updates to its functionality since its introduction, and it is also included in Windows 7, Windows 8, Windows 8.1, and Windows 10.

Windows Search was introduced in Windows Vista as a replacement for the previous Indexing Service to facilitate data discovery and management, promote greater rapidity of search results, and to unify desktop search platforms across Microsoft Windows it was also available as an optional download for Windows XP. Control Panel and Settings can also be searched. Windows Search creates a locally managed Index of files - documents, emails, folders, programs, photos, tracks, and videos - and file contents, as well as of non-file items including those of Microsoft Outlook for which users can perform incremental searches based on details such as authors, contents, dates, file names, file types, people, and sizes the Index stores actual prose from inside documents and metadata properties from other content. It was developed after the postponement of WinFS and introduced to Windows constituents originally touted as benefits of that platform.

Windows Search (also known as Instant Search) is a content index desktop search platform by Microsoft introduced in Windows Vista as a replacement for both the previous Indexing Service of Windows 2000 and the optional MSN Desktop Search for Windows XP and Windows Server 2003, designed to facilitate local and remote queries for files and non-file items in compatible applications including Windows Explorer. The advanced search pane in Windows Vista showing options to narrow search results

Windows 10 search not finding files