Re: windows file serch
You can use the Group Policy Editor to remove Search from the Start Menu and from Windows Explorer.
Computer Configuration | Administrative Templates | Windows Components Both Windows Explorer and Start Menu & Taskbar sections
You'd also have to disable access to the Command Prompt and disable running batch files.
Computer Configuration | Administrative Templates | Windows Components | System
Won't stop them from installing and using a 3rd party search tool, unless you've also blocked installing programs and removed any that are already installed.