Microsoft® Windows 2000 Knowledge Center

The Windows 2000 Emergency Repair Disk (ERD)


Using the Emergency Repair Disk to protect your Windows 2000 system

You get up one morning, and you find that you've over-slept and now you're late for work (or late to work on your at-home computer projects), it's rainy and drizzling outside and everything that can go wrong, does! Just an overall bad day. You sit down at your computer, turn it on and nothing. The computer starts, but it won't boot into Windows 2000. You do some checking and find that some startup files are corrupted. You think, "not a problem, I'll just dig out my ERD disk and fix it", what else can go wrong today?". Then it hits you, you've been thinking about making those Emergency Repair Disks, but never seemed to find the time. Murphy's Law, if it can go wrong, it will!

Unfortunately, things can and do go wrong with computers, even under the best of circumstances. If corruption occurs on your hard drive that, regardless of the cause, changes or corrupts your startup files or the Windows 2000 registry, you can use the ERD to get your system back into a bootable state. After you restart your Windows 2000 operating system, you can then opt to try and repair files or even perform a full recovery by restoring from your last system backup if necessary.

A problem that we see all too frequently comes from dual and multi-boot systems. One example is so simple that it often daunts the most experienced of users. Let's say you have a system running Windows 2000 that allows you to boot either into MS-DOS or Windows 2000 by using the boot loader menu. Now if someone were to make up a few MD-DOS disks and inadvertently use the MS-DOS SYS command on your C:\ drive, you will no longer be able to boot Windows 2000. MS-DOS will be the only operating system available. As you can see, a simple problem but when it's unexpected it's tough to locate.

While there are some rather elegant ways of accessing the Recovery Console even if the system refuses to boot as in our comment above, our focus here is on the presumption of the worst, in that the Recovery Console is inaccessible and you are left with just a failed system, your ERD, your setup disks and your Windows 2000 CD-ROM disk.

Using the Emergency Repair Disk
If your system does not start, and using safe mode or the Recovery Console is not an option, use of the Emergency Repair Disk (ERD) is inevitable. The best possible advice we can give you is to review your options, create a plan and follow it, but don't lose your patience!

Let's take a look at your options should a system failure occur and the Recovery Console is not an option.

Reminder! Make sure you create an Emergency Repair Disk while your computer is functioning well so that you are prepared in the event you need to repair system files. The ERD allows you to make only basic system repairs, such as to the system files, boot sector, and startup environment. The ERD does not back up data, programs, or the registry and is not a replacement for regular system backups.

Unlike the Windows NT 4.0 ERD, the Windows 2000 ERD does not contain a copy of the registry files. The backup registry files are in the folder %SystemRoot%\Repair folder. If you have installed Windows 2000 on your "C" drive, your backup registry files are at C:\WINNT\repair\RegBack. However, unless you have backed up these files recently, the files in this folder are from the original installation of Windows 2000. In any event, should there be a problem, they can be used to return your computer to a usable state.

If your registry files become corrupted or are accidentally erased, use the files in this folder to repair your registry without performing a full restore of the system state data. Although this method of recovery is recommended for advanced users only, it can be accomplished by using the Recovery Console commands. Recreate the ERD after each service pack, system date, or updated driver is installed. Be sure to make a copy of your current ERD and store it in a secure location

When you create an Emergency Repair Disk, it will contain only these files:

Autoexec.nt A copy of %SystemRoot%\System32\Autoexec.nt, which is used to initialize the MS-DOS environment.
Setup.log A log of which files were installed files, and Cyclic Redundancy Check (CRC) information for use during the Emergency Repair Process. This file has the read-only, system, and hidden attributes, and it is not visible unless you have configured My Computer to show all files.

The Emergency Recovery Process
Presuming that you have created an ERD, you can use it to help repair system files after starting the computer using either the Windows 2000 Setup CD or the Windows 2000 Setup floppy disks. However, either the Windows 2000 Setup CD or your slipstreamed/integrated installation point (server share, slipstreamed CD or second hard drive) will be required for replacing any damaged files.

Your Emergency Repair Disk must include current configuration information. Make sure that you have an ERD for each installation of Windows 2000 on your computer, and never use an ERD from another computer.

Note: You cannot repair all disk problems by using the ERD!

The following outlines the recovery process presuming that you cannot boot to your Windows 2000 CD-ROM, or that your installation point is on a CD-ROM disk or second hard drive and you will be using your ERD and four (4) Windows 2000 Setup Floppy Disks.

The Phases of the Recovery Process

  1. Insert the first disk of your setup floppy disks and restart the computer. This will begin the setup procedure and the examination of your hardware.

  2. Next, you will be asked to insert your Setup Disk #2 and touch enter. This will cause the setup program to load the Hardware Abstraction Layer along with other necessary files such as hardware support drivers, USB and SCSI upport, the partition manager and the like. When this is finished, you will be asked for Setup Disk #3.

  3. Setup Disk #3 completes the loading of your hardware driver support and scans the system bus looking for your SCSI bus (if it exists). You'll then be asked for Setup Disk #4.

  4. Setup Disk #4 finishes the process of loading your drivers by loading the appropriate CD-ROM driver, loading the FAT file system and then starting Windows 2000.

  5. The next screen you see will provide you will a group of choices:

    Windows 2000 Professional Setup

    Welcome to Setup.

    This portion of the Setup program prepares Microsoft<R>
    Windows 2000<TM> to run on your computer.

    • To set up Windows 2000 now, press ENTER.
    • To repair a Windows 2000 installation, press R.
    • To quit Setup without installing Windows 2000, press F3.
    ENTER=Continue  R=Repair   F3=Quit

  6. Select "R" to begin the actual repair process.

When you start the Emergency Repair Process, the following information is displayed on the screen:

This operation will attempt to repair your Windows 2000 system.
Depending on the type of damage present, this operation might or might not be
successful. If the system is not successfully repaired, restart Setup and choose
the option to recover a destroyed system or system disk.

Select one of the following repair options:

If you select Manual Repair, the registry files are not checked. If you select Fast Repair, and if the folder %SystemRoot%\Repair is accessible, the registry files are checked. If the folder %SystemRoot%\Repair is inaccessible (for example, due to file system corruption) the registry files are not checked.

If you choose Fast Repair, all repair options are performed.

Manual Repair allows you to select from the following three options:

Inspect Startup Environment   Inspect Startup Environment verifies that the Windows 2000 files in the system partition are correct. If any of the files that are needed to start Windows 2000 are missing or corrupted, Repair replaces them from the Windows 2000 Setup CD or your installation point, whichever the case may be. These include NTLDR and, and if the Boot.ini file is missing, it is recreated.

Verify Windows 2000 System Files   Verify Windows 2000 System Files uses a checksum to verify that each installed file is good and that it matches the file that was installed from the Windows 2000 Setup CD. If the recovery process determines that a file on the disk does not match what was installed, it displays a message that identifies the file and asks if you want to replace it. The Emergency Repair Process also verifies that startup files, such as NTLDR and Ntoskrnl.exe, are present and valid.

Inspect Boot Sector    Inspect Boot Sector verifies that the boot sector on the system partition still references NTLDR. The Emergency Repair Process can only replace the boot sector for the system partition on the first hard disk. The Emergency Repair Process can also repair the boot sector for the system partition on the startup disk.

If you choose Fast Repair, all repair options are performed.

If the Emergency Repair Process Does Not Fix Your System...

If you have performed the Emergency Repair Process and the computer still does not operate normally, you can use the Windows 2000 Setup CD to perform an in-place upgrade over the existing installation. This is a last resort before reinstalling the operating system. Note that the time required to complete the following procedure is equal to the time it takes to reinstall the operating system.

To perform an in-place upgrade of Windows 2000

  1. Insert your Windows 2000 Setup CD into the drive.
  2. Press Enter to install a copy of Windows 2000.
  3. When you are prompted to repair the existing Windows 2000 installation, press R.

Windows 2000 Setup performs an in-place upgrade of your existing installation. However, you might lose some customized settings of your system files.

