Google has recently discontinued Quick Search Box for Windows, which was included in Google Toolbar. If you liked the application, there's a way to use it, even if it's no longer available in Google Toolbar.
1. If you already have Google Toolbar for IE, it's likely that the toolbar has been updated to the latest version and you need to uninstall it. Just click the arrow next to the Google Toolbar wrench and select "Uninstall".
2. Install an older version of Google Toolbar for IE (6.3).
3. Now you can install the latest version of Google Toolbar from toolbar.google.com or wait until the application updates itself. You can also install the most recent version from FileHippo.