Prevent user from changing default homepage for IE.

1. Click Start button.
2. From the "Search programs and files" menu,
   
3. Key in "edit group policy" and from the menu click "Edit group policy"
   
4. Navigate to User Configuration > Administrative Templates > Windows Component > Internet Explorer.
   
   
5. Search for "Disable changing home page settings" and double click it.
6. Select Enable and key in your preferred Home Page.
7. Finally click Apply button.