DOCUMENT:Q102793  26-AUG-1993  [W_NT]
TITLE   :Unable to Load MS-DOS with Windows NT OS Loader
PRODUCT :Windows NT
PROD/VER:3.10
OPER/SYS:WINDOWS
KEYWORDS:

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The information in this article applies to:
 
 - Microsoft Windows NT operating system version 3.1
 - Microsoft Windows NT Advanced Server version 3.1
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SYMPTOMS
========
 
If BOOTSECT.DOS is corrupt, the MS-DOS operating system may be
unavailable and one of the following error messages may be received
when MS-DOS is selected from the OS Loader Menu during startup:
 
   Non-System disk or disk error
   Replace and press any key when ready
 
   Couldn't open boot sector file
   multi(0)disk(0)rdisk(0)partition(1):\BOOTSECT.DOS
 
CAUSE
=====
 
These error messages are caused by a missing or corrupt BOOTSECT.DOS
file. BOOTSECT.DOS is a hidden, system, read-only file used by NTLDR
to start the MS-DOS operating system.
 
RESOLUTION
==========
 
Because Windows NT is able to load correctly and the boot sector
itself is not damaged, the Emergency Repair Disk may not detect a
problem. To force the Emergency Repair Disk to rewrite the boot files,
the following workaround must be used.
 
NOTE: The Windows NT Emergency Repair Disk must be available and
working correctly for the following procedure to succeed. To test the
Emergency Repair Disk, press the SPACEBAR key when you are prompted
while Windows NT is loading. The Repair menu should appear.
 
1. Load Windows NT and use File Manager to back up the Emergency Repair
   Disk and any critical data before proceeding.
 
2. Shut down and reboot the system to a bootable disk that contains the
   MS-DOS program SYS.COM.
 
3. From the bootable disk in drive A, use the following command to 
   remove the Windows NT boot sector:
 
      SYS C:
 
   You should receive a "System Transferred" message.
 
   SYS.COM replaces the partition boot sector, which loads NTLDR, with
   an MS-DOS boot sector that loads MSDOS.SYS and IO.SYS.
 
4. Reboot the system with the Windows NT Setup Disk number 1 in drive
   A. When prompted, type R for Repair. Setup will then prompt for the 
   Emergency Repair disk, read data from it, and prompt again for the 
   Setup disk to be inserted in drive A. 
 
5. The Windows NT Setup menu will be displayed. Select only Verify
   Boot Files on drive C. Highlight Continue (perform selected Tasks) 
   and press ENTER.
 
   After Setup rebuilds the damaged files, you will be prompted to
   reboot the machine.
 
The Repair process will replaces NTLDR, NTDETECT.COM, BOOTSECT.DOS,
BOOT.INI, and the partition boot sector so that the original dual-boot
configuration will be restored.
 
Additional reference words: 3.10 tshoot dual boot

KBCategory:
KBSubcategory: winnt

=============================================================================

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