by Lance Jensen Executive Software Technical Support Director
A current Emergency Repair Disk (ERD) is one of the vital tools needed to maintain
a Windows NT system. Unfortunately, most Windows NT sites do not maintain their
ERDs because many administrators have never been taught how to use them. We would
like to help correct that situation. In this article the designation, "%systemroot%"
will refer to the system folder. The default name is WINNT, but whoever actually
installed Windows NT on your system may have given it a different name. Many of
the files in the %systemroot% tree are hidden files, and many are read-only. To
see hidden files, start Windows Explorer, go to the Menu Bar and click "View",
"Folder Options", and the "View" tab. In the Advanced Settings
box, under "Hidden files", click the "Show all files" button,
then OK. You will now be able to see all files. Before you can copy or edit a
read-only file, you must right-click the file, then click "Properties".
Under the General tab, in the Attributes section, uncheck the Read-only box. What
Is the ERD? The ERD is a floppy disk containing the files in the %systemroot%\repair
folder, that are the configuration files and Registry information. If your Registry
or startup environment become damaged in any way, the ERD will usually be able to
fix it. However, the ERD is not a substitute for a full backup. It's more like
a "Backup Lite" which can frequently save you from having to do an entire
restore from backup. The files "sam._" and "security._" on
the ERD are often not kept updated, because they can be too big to fit on a floppy.
You probably won't see this except on a server with over a thousand users and groups.
If these files are too big for a floppy, you can back them up using your regular
backup utility or the regback.exe utility in the Windows NT Resource Kit, and you
can save copies in a special folder on the disk. I strongly recommend keeping several
ERDs for each machine. The first one should be made when you first install Windows
NT. If you did not make one at that time, now is a good time to do so. Then make
a second copy and store one off-site. As you expand and change your Windows NT
system, keep these original ERDs as a safety measure. For convenience, you could
also create a second repair folder (let's call it \repair2) and copy the original
files from \repair into it. If you do back up the "sam._" and "security._"
files (which you should do if you can), you may some day find that you can no longer
fit all of the files on a floppy disk. Remember that the entire contents of the
%systemroot%\repair folder are copied to the ERD, so you must keep its size under
1.44MB. Should the folder grow too large, take the ERD from the original Windows
NT installation (or from \repair2) and copy ONLY the "sam._" and "security._"
files into the %systemroot%\repair folder. The folder should now be small enough
to make an ERD. If it's not, you need to reduce the size of setup.log. Edit setup.log
and locate the line "[Files.WinNt]", which is followed by a long list
of file names. You can safely delete any of these file names that do not begin
with %systemroot%\SYSTEM32\. At some point in this list you may find a line "[Files.InRepairDirectory]";
do not delete anything after this line! There are two things you should keep in
mind: 1. The files "sam._" and "security._" contain your security
database. If these files are included on the ERD, then your system could be invaded
if a criminal should get his hands on it. Keep all copies of the ERD safe and secure,
from theft as well as from damage. 2. When you do a repair from an ERD, the "sam._"
and "security._" files may be replaced with the ones from the ERD. If
these files were too large to fit on the ERD, you have to recover them from someplace
else. The easiest handling for this is a third folder, \repair3, in which you copy
just the "sam._" and "security._ files". Making an ERD The
ERD is created using the RDISK utility. You should make a new one whenever you
make any significant change to the system, such as adding a new application or Service
Pack, or changing the Registry. This is the procedure to use if you are including
the security data on your ERD: 1. If you have not already done so, create \repair2
and copy the files from \repair into it. If you do not have an original ERD, make
one now by using these steps, but leave off the /S switch in step 3. 2. Click Start,
go to Programs, and click Command Prompt. 3. Type RDISK /S <ENTER>. 4. When
prompted "Do you want to create an Emergency Repair Disk?", respond "Yes".
5. Follow the prompts. 6. Label and date the ERD. The /S switch in step 2 is
necessary because the files in the %systemroot%\repair folder are not updated when
your system is modified; you have use RDISK to do it manually. The /S switch tells
RDISK to update the repair files, including the "sam._" and "security._"
files. This is the procedure to use if you are not including the security data
on your ERD: 1. If you have not already done so, create \repair2 and copy the
files from \repair into it. If you do not have an original ERD, do steps 6 to 9
now to make one. 2. Click Start, go to Programs, and click Command Prompt. 3.
Type RDISK/S- <ENTER>. (The /S- switch updates the files, but does not proceed
to create an ERD.) 4. Copy the "sam._" and "security._" files
from \repair into \repair3. 5. Copy the "sam._" and "security._"
files from \repair2 into \repair. 6. Type RDISK <ENTER>. 7. Click the "Create
Repair Disk" button. 8. Follow the prompts. 9. Label and date the ERD. The
ERD just created can be used to get your system running again if something goes
wrong while modifying your system. Now go ahead and make the system changes. When
you have finished and tested and you are satisfied that the change is done, repeat
the steps to update your system with your new modifications, and make two new ERDs.
The second ERD should be stored with your offsite backups. If you don't keep offsite
backups, you may not want a second ERD; I like to have one in case the first copy
gets damaged. Is the ERD Really Needed? You may never have made an ERD, or you
might lose it, or it might get damaged. If you ever have to do a repair without
an ERD, you have several options: 1. Sometimes you can do a repair without any
ERD at all. If the repair procedure can find your Windows NT install directory,
it may be able to directly access the repair directory. Sometimes it works, sometimes
it doesn't. 2. If that fails, you may be able to create a new ERD. First you
need a floppy disk that was formatted on a Windows NT system. If the %systemroot%\repair
folder is on a FAT partition, you can boot to a bootable DOS floppy and copy the
repair files to the new floppy. Some are hidden, so be sure you get them all.
The files are: autoexec.nt config.nt default._ ntuser.da_ sam._ security._ setup.log
software._ system._ It's harder to access the folder if it's on an NTFS partition,
but here are some ways to do it: A. There are applications available that run
under DOS and can read NTFS partitions. You can use one of these to create the
floppy as described above. B. You could move the hard disk to another machine that
is running Windows NT and create the floppy there. C. You could make another Windows
NT installation on the same machine, boot into it, and make your new floppy. 3.
Last, you may be able to copy the files from a backup tape. You might restore
%systemroot%\repair folder, or copy it to another machine. 4. If all of this fails,
you must reinstall Windows NT. As you can see, it's a lot simpler to make sure
you always have a current ERD. Next Part 2 of this series will be step-by-step
instructions for repairing your system using the ERD. If you have any questions,
or any advice or tips regarding the ERD which you would like to share, please send
them in. I can compile them into an additional article or two.
------------------------------ Lance
Jensen is Executive Software
ace Tech Support Director, and has great experience with both Windows NT and Digital's
OpenVMS operating systems. He can be reached at dknt_support@executive.com.
Please feel free to write to him with questions or comments about this article. Visitit the Execute Software website: http://www.execsoft.com/ @Macarlo, Inc. @Macarlo's Shareware & Web OS/2 Java Lobby Member
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