Internet Explorer question

IE 6
Silly question that im embarassed to ask but here goes. I cannot figure out how to remove the Drop Down boxes that remember what ive typed in the past. For example, when i go to yahoo.com and type the letter “T” in the search box, a drop down appears and lists everything ive searched for on yahoo and google that begins with T.
Ive checked in Internet Explorer settings and have purused the registry for a key that will turn it off. I vagely recall in IE 5 that there was a setting that said “drop down displays automatically” and it could be turned off. I dont even have an advanced tab. This is for a home user.