||This article may require cleanup to meet Wikipedia's quality standards. (October 2010)|
Desktop search is the name for the field of search tools which search the contents of a user's own computer files, rather than searching the Internet. These tools are designed to find information on the user's PC, including web browser histories, e-mail archives, text documents, sound files, images and video.
One of the main advantages of desktop search programs is that search results arrive within a few seconds or less; Microsoft Windows search companion "can be some help, but it searches through Windows files and folders only, not e-mail or contact databases, and unless you enable the Indexing Service (in Windows 2000 or XP), the Windows search tool is extremely slow." MS Windows Vista enables the indexing service by default.
A variety of desktop search programs are now available; see this list for examples.
Desktop search is emerging as a concern for large firms for two main reasons: untapped productivity and security. On the one hand, users needs to be able to quickly find relevant files, but on the other hand, they shouldn't have access to restricted files. A commonly cited statistic states that 80% of a company's data is locked up inside unstructured data — the information stored on an end user's PC, the directories (folders) and files they've created on a network, documents stored in repositories such as corporate intranets and a multitude of other locations. Moreover, many companies have structured or unstructured information stored in older file formats to which they don't have ready access.
Companies doing business in the United States are frequently required under regulatory mandates like Sarbanes-Oxley, HIPAA and FERPA to make sure that access to sensitive information is 100% controlled. This creates a challenge for IT organizations, which may not have a desktop search standard, or lack strict central control over end users downloading tools from the Internet. Some consumer-oriented desktop search tools make it possible to generate indexes outside the corporate firewall and share those indexes with unauthorized users. In some cases, end users are able to index — but not preview — items they should not even know exist.
Historically, full desktop search comes from the work of Apple Computer's Advanced Technology Group, resulting in the underlying AppleSearch technology in the early 1990s. It was used to build the Sherlock search engine and then developed into Spotlight, which brought automated, non-timer-based full indexing into the operating system.
Most desktop search engines build and maintain an index database to achieve reasonable performance when searching several gigabytes of data. Indexing usually takes place when the computer is idle and most search applications can be set to suspend it if a portable computer is running on batteries, in order to save power. (One exception would be tools which only search filenames — not the files' contents — e.g. Search Everything does this for NTFS volumes only, enabling it to build its index from scratch in just a few seconds.)
Desktop search tools typically collect three types of information about files:
- file and folder names
- metadata, such as titles, authors, comments in file types such as MP3, PDF and JPEG
- file content (for supported types of documents only)
Besides programs that use indexing, there are many programs that open and search files on the fly. Their disadvantage is that they can only feasibly search a certain folder tree, not the entire computer, but their great advantage is that they do not burden the computer's resources with indexing. Also, they are less likely to give incorrect results due to the index lagging behind.
To search effectively within documents, the tools need to be able to parse many different types of documents. This is achieved by using filters that interpret selected file formats. For example, a Microsoft Office Filter might be used to search inside Microsoft Office documents.
The sector attracted considerable attention from the struggle between Microsoft and Google. According to market analysts, both companies are attempting to leverage their monopolies (of web browsers and search engines, respectively) to strengthen their dominance. Due to Google's complaint that users of Windows Vista can not choose any competitor's desktop search program over the built-in one, an agreement was reached between US Justice Department and Microsoft that Windows Vista Service Pack 1 would enable users to choose between the built-in and other desktop search programs, and select which one is to be the default.
See also 
- "Conquer Information Overload", PC Magazine.
- "Security special report: Who sees your data?", Computer Weekly, 2006‐4‐25.
- "The current state of video search", by Niall Kennedy
- "The current state of audio search", by Niall Kennedy
- "Search wars hit desktop computers". (Oct 2004) BBC News
- "Microsoft agrees to change Vista Desktop Search Tool" (Jun 2007)
- Keeper Finders, by Paul Boutin, Slate, December 31, 2004 — A comparison of Google, Ask Jeeves, HotBot, MSN and Copernic desktop search tools.
- GoebelGroup.com's desktop search tools comparison chart - Date of last update: 15 January 2007.
- A detailed comparison of desktop search tools - dated 2004.
- Comparison of desktop search software - Date of last update: March 2008