The History list is a file, and therefore it begins to take up space as it grows larger. This is particularly true if you set a fairly long expiration time. It makes sense to clear the list every now and again. To do this, open Internet Explorer and click “Tools / Internet Options / Click Clear History in the History section and you’re all set. Before you do this, however, make sure that you make note of any sites that are important (like ones that you have forgotten to bookmark).