By default, Safari for Windows uses Google as the default search engine. If you are one who prefers Yahoo! instead, follow these steps to make it the default:
1. Open Safari.
2. Click Edit and select Preferences.
3. Under the General tab, use the Default Search Engine dropdown and select Yahoo!.
4. Close the Preferences window.
You can also quickly switch back and forth between Google and Yahoo! as the default search engine by using the search box at the top of the browser. Simply click the downward pointing arrow and select either Google or Yahoo! for it to become the default.