boot disk

What is a boot disk (startup disk) and why would I need one?

A boot disk (sometimes called a startup disk) was a type of removable media,
such as a floppy disk, CD, or DVD, that contained Windows startup files that your computer could use to start Windows,
 if the Windows system files on the hard disk became damaged or unusable.

In this version of Windows, you can create a system repair disc that contains the System Recovery Options menu.
This menu, also located both on your computer's hard disk and on the Windows installation disc,
contains special recovery tools that can help get Windows running again.