Google Quick Search Box is discontinued
Google has apparently discontinued their Quick Search Box product which was bundled with their Google Toolbar.
The feature is still available through Google Desktop though not everyone likes to have it installed on their machines.
There are however some ways to get back Quick Search Box on your machine. You can install an older version of the toolbar which is still available online through third party sites.
Google Toolbar would be updated automatically but you would still retain the QSB functionality.