Internet Explorer History is a record of all Web sites that have been visited during a particular period of time. The default History setting is 20 days, which most people find sufficient. Generally there is no reason to change this setting for any other reason other than personal preference. Be warned though, if your History folder gets too large it may corrupt, so don't try to keep the maximum number of days in history (99 days).
To reduce or increase the number of days a site is kept in history
In Internet Explorer 6, click Tools, click Internet Options, and then under History, adjust the number of days.
In Internet Explorer 7, click Tools, click Internet Options, and then click the Settings button for Browsing History.
We can control how our browsing history is displayed in the History pane. To access the History pane in Internet Explorer 6, click the History button on the toolbar. In Internet Explorer 7, click on Tools, then Toolbars.
We can select view by date, view by site, view according to most visited sites, and viewed in order visited today. I personally find the view by date to be the most useful when searching an extended history. The ability to search in the History folder is simple yet powerful, but will only work if we type the search terms exactly as they appear on cached Web page, or in its URL or page title.
Sometimes people use their History folder as a type of pseudo-Favorites folder. This is not really a good idea. The History folder is dynamic and URLs may disappear if left unvisited for long enough (for example if you go away on holiday and do not turn on your computer for an extended period of time). The sites that you want to ensure are preserved should be saved as a Favorite (click the Favorites menu, and then select Add to Favorites).
An added benefit of saving URLs as Favorites is that you are able to export a backup of your Favorites for safe keeping, or to copy to another computer. It is not possible to export and import the History folder in this way.
To export your Favorites, click the File menu, and then select Import and Export to start the Import/Export wizard. Decide what you want to import or export, and have a floppy disk or USB key ready to copy the file to.
An in-depth discussion about the advanced features of Internet Explorer History and Favorites can be found in my article Data in depth: Get more from Internet Explorer's Favorites and History