This same problem was just discussed in the Newbies Forum and you might find a fix on it. Just click on this link and follow the threads. Hope this helps for you.
Using XP Home - On search engines,such as google, how do I remove previous requests on the dropdowns. When I begin typing and if I start eg with a letter `G` any other previous requests which started with `G`appear which I find annoying.
Can anyone help?