You can clear the search history of previous searches by following the
procedures below:

"In Internet Explorer 5 or higher, select "Tools" from the menu, then
"Internet Options" and then choose the "Content" tab. Next, look for
the button at the bottom that says "AutoComplete." Click on the button
which will make the AutoComplete Settings window appear. In it, click
on the "Clear Forms" button to delete all your stored form entries."