Unleashing Windows: The Windows NT 4.0 Emergency Repair Disk (Part
II)
Part I covered how to create an Emergency Repair Disk,
but now that we have one made, we have to know what can be done
with it when something goes wrong with Windows NT. In this
article, we'll examine how the Emergency Repair Disk can be used
to repair a damaged NT installation.
The first thing to understand is that the ERD is not a
bootable disk, therefore, you have to use it in conjunction with
the Windows NT 4.0 CD-ROM and the original 3 floppy disks that
come with Windows NT. If your original 3 installation floppies
are missing, damaged, or corrupt, you can create them by running
Winnt.exe /ox to build them using 3 formatted floppy disks.
To actually use the ERD, you boot a damaged NT system
with the first of the 3 installation diskettes. You'll go through
the boot process and use the second diskette. After you insert
the second diskette, you'll be prompted with the main setup
screen. Normally, you'd use the full installation option
displayed, but in this case you'll select R to start the
Emergency Repair process.
With the Emergency Repair Disk, you'll be able to do
any (or all) of the following options:
- Inspect Registry Files
- If this option is checked, then the repair process will
provide a list of the Registry files it can check and
restore. The Registry options are:
System (System
Configuration) - This
restores the HKEY_LOCAL_MACHINE\System key based on the
information on the Emergency Repair Disk
Software
(Software Configuration) -
This restores the HKEY_LOCAL_MACHINE\Software key.
Default
(Default User Profile) -
This restores the information for the .DEFAULT subkey of
HKEY_USERS. The .DEFAULT subkey is used when no users are
actively logged into the computer, such as when the
CTRL+ALT+DEL login screen is displayed. To accurately use
this option, it's recommened that the /S parameter be
used with the RDISK utility.
NTUSER.DAT
(New User Profile) - This
restores the %systemroot%\Profiles\Default
user\Ntuser.dat. This should not be confused with the
option shown above, which restores a Registry entry.
Security
(Security Policy) and SAM (User Account Database)
- If the ERD was created using RDISK with the /S
parameter, then the accounts that were defined when the
utility was run are created. Otherwise, the default NT
accounts are created.
- Inspect Startup Environment
- This option checks for the intial startup files on a
system are correct, corrupt, or missing. If a file is
missing or corrupt, it will be replaced by ones created
from the Windows NT 4.0 CD-ROM. Additionally, if Windows
NT is not listed in the boot.ini file, the repair process
will automatically add it to that file on Intel-based
systems.
- Verify Windows NT System
Files - This option uses checksum
values, found in the Setup.log file on the ERD, to match
the files on the disk with the ones on the CD-ROM. This
option also checks the NTLDR and Ntoskrnl.exe to ensure
that they are present and the correct versions.
- Inspect the Boot Sector
- This option check to make sure the the system partition
is still able to start Windows NT. If it is damaged, it
will restore the boot sector information.
Keep in mind a few things about using the Emergency
Repair Disk to repair a system. It will only bring back
information from the last time the RDISK utility was run. So, for
example, if you created a new user or added new hardware since
running the RDISK utility, then that information will not be
restored.
Additionally, the Emergency Repair Disk process relies
on the correct disk and partition configuration. If you changed
the disk or partition layout on a system, be sure to update the
ERD! This is critical, since if the disk configuration has
changed, the Emergency Repair Disk process may not be able to
continue. This also included configuring RAID fault tolerance,
such as mirroring or disk striping with parity.
That covers the basics of using the Emergency Repair
Disk to recover a NT system. The Emergency Recovery Disk is a
valuable tool to bring back a failed NT system. Remember: the ERD
should always be kept up to date to increase the probability of
completely restoring the Windows NT system!
Richard Neff is a Microsoft Certified Professional,
certified as a Systems Engineer with elective exams in
Microsoft Mail and Systems Management Server (SMS). He is
also a Product Specialist in Microsoft Excel 5.0 and
Microsoft Word for Windows 2.0/6.0. He has a B.S. in Computer
Science from VMI and has worked with personal computers for
over 15 years. He is a contributing author to the books Windows NT 4.0 Installation and
Configuration Handbook and Windows NT 4.0 Advanced Technical
Reference, both published by Que
Publishing. He has formed his own computer consulting
company, Network Technologies Group, which specializes in
Novell Netware, Microsoft Windows NT, and Microsoft
BackOffice solutions. Network Technologies Group is located
in Blacksburg, VA and also has a Web site at http://www.net-tech-group.com
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