Q: Can I add other search providers to the Search dropdown menu?

A: The Toolbar Search Box makes it quick and easy for you to search the Web directly from the upper-right corner of the browser using your favorite search providers. Enter your search words, and then choose a search provider from the drop-down list. To add more providers, click the drop-down arrow and then click Find More Providers... to easily add more providers to your list.

Note: This information provided by Microsoft.