The search engine formerly known as MSN Search changed to Live Search and then recently to Bing.

The Bing search engine (formerly Windows Live Search and MSN Search) is the name of Microsoft's web search engine, designed to compete with the industry leaders Google and Yahoo!. Bing is accessible through Microsoft's Live.com and MSN.com web portal. Currently, Live Search is the fourth most used search engine after Google, Baidu, and Yahoo!

The search engine offers some innovative features, such as the ability to view additional search results on the same web page (instead of needing to click through to subsequent search result pages) and the ability to dynamically adjust the amount of information displayed for each search-result (i.e. just the title, a short summary, or a longer summary). It also allows the user to save searches and see them updated automatically on Live.com.

On early 2009, Microsoft started internal testing of a new search engine, called Kumo, which could be a replacement of Live Search
MSN Search was a search engine by Microsoft that comprised a search engine, index, and web crawler. As of September 12, 2006, MSN Search is now Live Search. This offers users the ability to search for specific types of information using search tabs that include Web, news, images, music, desktop, local, and Microsoft Encarta. MSN Search aims to make its over 2.5 billion worldwide queries each month "more useful by providing consumers with improved access to information and more precise answers to their questions." A configuration menu is available to change the default search engine in Internet Explorer.

MSN Search first launched in the fall of 1998 using search results from Inktomi. In early 1999, MSN Search launched a version which displayed listings from Looksmart blended with results from Inktomi except for a short time in 1999 when results from AltaVista were used instead. Since then Microsoft upgraded MSN Search to provide its own Microsoft-built search engine results (list of web addresses with samples of content that meet a user's query), the index of which is updated weekly or even daily. The upgrade started as a beta program in November 2004 (based on several years of research), and came out of beta in February 2005. Image search was powered by a third party, Picsearch. The service also started providing its search results to other search engine portals in an effort to better compete in the market.

The first public beta of Live Search was unveiled on March 8, 2006, with the final release on September 11, 2006 replacing MSN Search.On March 21, 2007, it was announced that Microsoft would separate its Live Search developments from the Windows Live services family. Live Search was integrated into the Live Search and Ad Platform headed by Satya Nadella, part of Microsoft's Platform and Systems division. As part of this change, Live Search was consolidated with Microsoft adCenter.
In the roll-over from MSN Search to Live Search, Microsoft stopped using Picsearch as their image search provider and started performing their own image search, fueled by their own internal image search algorithms.