If you use a toolbar such as the Google or Yahoo toolbars, you probably won’t want to see the built-in search box in Internet Explorer 7. There’s a quick registry fix that you can do to enable / disable this.
This registry fix works by adding in the DWORD value NoSearchBox, with the value set to 1, to the following registry key:
Hide Search Box
Show Search Box
Here’s what it looks like in action, with the search box hidden
This should work for IE7 on Windows Vista as well as on Windows XP.