How to Repair Windows NT System Files Without a CD-ROM Attached

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Article ID: 150497 - View products that this article applies to.
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If you perform a Windows NT Setup from a non-supported CD-ROM drive, or you set up Windows NT over the network by doing a WINNT or WINNT /B setup, you will not be able to repair system files during the emergency repair process without a supported CD-ROM attached.

If you choose "Verify Windows NT System Files" on the repair menu, the repair process will read the Setup.log located on the emergency repair disk (ERD). This file contains the name of the Windows NT system files to check along with the cyclical redundancy check (CRC) value of each file.

If the repair process finds a system file that is corrupted or missing, it will prompt you, asking if the file should be repaired. If you reply yes, and your system contains no CD-ROM drive, the repair process will prompt you for a Windows NT Setup floppy disk that contains the file that needs repair.

Because Windows NT server only ships on compact disc, it will not be possible to provide a valid Windows NT Setup disk to repair the file.

Before proceeding, please review the following Knowledge base articles if any Windows NT Service Pack is installed:

146887Repairing Windows NT After the Application of Service Pack 3

162837Replacing TCPIP after SP2 causes STOP 0x00000050

148262Removing Windows NT 3.51 SP4 or SP5 May Cause Logon Failures


To correct this problem you will need to run through the repair process twice. The first time through, choose not to replace the files that are found to be missing or corrupt, but write down a list of these files. Next, modify the Setup.log file on the ERD as outlined below, and then perform another repair process, this time choosing to replace the files.

**NOTE** - NT V4.0 requires that the setupdd.sys located on setup diskette
           #2 be replaced with one from NT V4.0 Service pack#2 or later in
           order to perform a repair without a cd-rom attached.

  1. Make a copy of the hidden read-only file called Setup.log found on the ERD.
  2. Remove the hidden read-only attributes.
  3. Using Notepad, modify the entry for each file that needs repair by adding a "path","media name","tag file name" entry at the end of each line.

    Example before modification:

    WINNT\system32\clipsrv.exe = "clipsrv.exe","1168c"
    WINNT\system32\ = "","16281"
    WINNT\system32\control.exe = "control.exe","16566"

    Example after modification:

    WINNT\system32\clipsrv.exe = "clipsrv.exe","1168c","\","floppy","d1.txt"
    WINNT\system32\ = "","16281","\","floppy","d1.txt"
    WINNT\system32\control.exe = "control.exe","16566","\","floppy","d1.txt"
  4. On a separate disk, make a file called the same name as the "tag file name" at the end of the files you modified (in the example above, this file will be called d1.txt) and place it in the root directory of the diskette.
  5. Finally, on a machine that has a CD-ROM drive installed, copy the files that need repair from the Windows NT Setup compact disc to the floppy disk.
If multiple diskettes are required use a different tag file name in the setup.log to correspond to the different diskettes IE: d1.txt, d2.txt ...

Now perform another repair process, and this time choose to repair the files.
  1. The repair process should prompt you to insert the floppy disk that you made, which contains the files to repair.
  2. If the files cannot all fit on a single disk, simply delete from the disk the files that have already been repaired and copy the additional files onto the same disk and continue with the repair process or use different diskettes with different tag file on each one to match the tag file entry in the setup.log.


Note: This Process assumes that the system can still boot at this time or the system is in a dual boot environment with access to the source media. This process also assumes adequate disk space to be available of approximately 100mb.

With some proactive planning, one could have a copy of the installation CD-ROM \i386 directory on the hard disk of the system. When the repair process is runs it refers to those repair files already located on the local hard disk.

To run the repair process off the Hard disk, please use the following steps.
  1. Create a directory on any Hard disk to hold the system files. For this example c:\repair.
  2. Copy the system files from the retail CD-ROM to the Hard Dive keeping the directory structure intact. The platform directory (i386) and the CDROM_W.40 file for Workstation or CDROM_S.40 file for Server must be copied at the very minimum. Upon completion your c:\repair directory should contain the following:

          \i386    (directory containing all the system files)
    CDROM_W.40     (For Workstation in the root of \repair)
    CDROM_S.40     (For Server in the root of \repair)

  3. Create the three setup boot floppies using the following commands on the Windows NT installation CD-ROM:

    - For Win95/DOS = CD to \i386 directory then Winnt /ox
    - For Windows NT = CD to \i386 directory then Winnt32 /ox Note: Make sure to replace the file setupdd.sys on disk #2 with the updated file from the Windows NT Service Pack-2 or later.

    168015Files Not Replaced When Running Emergency Repair

  4. Using any text editor make the following changes to the txtsetup.sif file on your first setup boot disk. The lines that you must change are commented with a ";***" on the previous lines.

    ; SetupSourceDevice is optional and specifies the nt device path
    ; of the device to be used as the setup source. This overrides
    ; the CD-ROM or winnt local source.
    ;***remove the semicolon from the following line and make sure it
    ;***references the physical location of the system files.
    ;***In the example this will be partition1 since C: is the first
    ;*** partition on the disk.
    SetupSourceDevice = \device\harddisk0\partition1
    ; SetupSourcePath specifies the path relative to the source device
    ; where the setup source tree is to be found.
    ; All media descriptors are relative to this.
    ;*** Change the "SetupSourcePath" line to the path of your system
    ;*** repair files.
    ;*** In the example, I would change the variable to equal \repair.
    MajorVersion = 4
    MinorVersion = 0
    OsLoadOptions = "/nodebug"

  5. Save the changes to the floppy and start the repair process by booting the system using the modified setup boot disk. The repair process will operate as normal but will not prompt the user for a CD-ROM.
Note: Again that this process assumes that the flat already exists on the hard disk or user can boot to another OS and copy the files over. If you are in a situation where the system cannot boot or cannot afford the extra HD space that the system files will take up, you may want to use the above process to create the structure on a spare HD or removable media (Jazz drive, etc...). In the event of a failure that requires the system files to be repaired, you can attach the drive to the system.


Article ID: 150497 - Last Review: November 1, 2006 - Revision: 2.1
  • Microsoft Windows NT Workstation 3.5
  • Microsoft Windows NT Workstation 3.51
  • Microsoft Windows NT Workstation 4.0 Developer Edition
  • Microsoft Windows NT Server 3.5
  • Microsoft Windows NT Server 3.51
  • Microsoft Windows NT Server 4.0 Standard Edition

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