Desktop search tools search within a user's own computer files as opposed to searching the Internet. These tools are designed to find information on the user's PC, including web browser history, e-mail archives, text documents, sound files, images, and video. A variety of desktop search programs are now available; see this list for examples. Most desktop search programs are standalone applications. Desktop search products are software alternatives to the search software included in the operating system, helping users sift through desktop files, emails, attachments, and more. Desktop search emerged as a concern for large firms for two main reasons: untapped productivity and security. According to analyst firm Gartner, up to 80% of some companies' data is locked up inside unstructured data — the information stored on a 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. The sector attracted considerable attention in the late 2004 to early 2005 period from the struggle between Microsoft and Google. According to market analysts, both companies were 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 cannot 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. As of September 2011, Google ended life for Google Desktop. Technologies Most desktop search engines build and maintain an index database to improve performance when searching large amounts of data. Indexing usually takes place when the computer is idle and most search applications can be set to suspend indexing if a portable computer is running on batteries, in order to save power. There are notable exceptions, however: Voidtools' Everything Search Engine, which performs searches over only file names, not contents, is able to build its index from scratch in just a few seconds. Another exception is Vegnos Desktop Search Engine, which performs searches over filenames and files' contents without building any indices. An index may also not be up-to-date, when a query is performed. In this