Change the Default Internet Explorer Search Page

Start/Run/Regedit

“HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main”
Value Name: Search Bar, Data Type: REG_SZ (String Value), Value Data: Search URL. Create a new String value, or modify the existing value, called 'Search Bar' and edit the value according to the settings below.

Exit your registry, you may need to restart or log out of Windows for the change to take effect.

Note: This tweak can also be applied on a per-user basis under the [HKEY_CURRENT_USER] hive.