By default, Microsoft's Bing search engine tracks every query you enter. This behaviour starts the first time you run a Bing search and the data is not automatically cleared until one of two things happen: 28 days have passed, or you sign out of your Windows Live ID account. If you are concerned about your privacy and want to prevent anyone from viewing your search history, Bing gives you the option to manually clear this data instead. Once you know where to look, removing your history from Bing requires just a few clicks.
Navigate to the Bing home page (see "Resources" section.)
Click the "Search History" link on the left side of the window.
Click the "EDIT HISTORY" heading to view the list of available options.
Click the "Clear" link.
Click the "Yes, clear all search history" link.