This article was previously published under Q156328
During Windows NT 4.0 Setup, you are given the option to create anEmergency Repair Disk (ERD). Microsoft recommends that you create an ERDduring Setup so that you will have the proper tools in case fault recoverybecomes necessary.
Maintaining a current ERD is just as important as having a current systembackup. When system configuration changes are made (such as installing newsoftware or changing software configuration, altering networkconfiguration, hardware changes, operating system updates) you shouldupdate your ERD with the Rdisk utility included with Windows NT.
Following is an excerpt from the Windows NT 3.51 Resource Kit Update 2,page 127:
A current Emergency Repair Disk is your most valuable tool in recoveringinformation that you need to start your system. The Emergency Repair Diskis intended to provide just enough recovery to restore a system to abootable state and is not a replacement for regular backups.
Windows NT Server and Windows NT Workstation include the RDISK commandfor building and maintaining repair information. You can use this tool toupdate the repair information stored in the Winnt\Repair folder and tocopy the information to a floppy disk. You can use the Emergency RepairDisk to replace damaged system files, restore damaged or incorrectregistry information, and rebuild the startup environment.
You should update the repair information and create a new Emergency RepairDisk any time you change the system configuration in any significant way.For example, if you add or remove hardware from the system or change thedisk drive configuration, you should update the repair information.
To maintain your current registry configuration, you must update your ERD. Otherwise, each repair disk only contains the registry information from the time Windows NT was first installed. To create an updated ERD, use one of the following methods:
Type rdisk /s in the Open box.
Type rdisk in the Open box, and then click Update Repair Info.