For information about generic boot/recovery discs, see Recovery disc
A Microsoft Windows emergency repair disk is a specially formatted bootable (for some Windows operating systems) media made by some Windows operating systems that contains information about a particular Windows installation, first seen in Windows NT 4.0. This disk can be used to restore a computer to a bootable state if the registry or other fundamental system components are damaged due to a malware infection or anything else that could make the operating system unbootable.
Windows 2000 uses what is called an emergency repair disk but it is not bootable. Windows XP uses something very similar to the Windows 2000 emergency repair disk, but it is called automated system recovery.
An emergency repair disk is available for Windows, starting with Windows Vista. It can be used to access a recovery console as well as repair non-bootable states.
An emergency repair disk is a diskette that creates backups of important system files and settings and is used to help troubleshoot and fix issues for Microsoft Windows NT and Windows 2000 users. It is used in conjunction with the Windows repair option and you will be prompted for the diskette when needed. Note: The emergency repair disk is not to be confused with a standard boot diskette as it cannot be used alone. An emergency repair disk is capable of verifying the boot sector is not corrupt. Repairing any start-up files. Locate any missing or damaged system files.