August 8, 1998
I'm going to share with you the undocumented information for using the Microsoft Emergency Recovery Utility found on the Windows 95 CD-ROM. I discovered this a few years ago. Even though it is not new, I don’t know of any other place this information appears in print. What’s more, it is absolutely one of the most important things you can know to avert disaster on your Windows 95 or Windows 98 systems.
Background
The Windows system registry is comprised of two files on Windows 98 (SYSTEM.DAT, and
USER.DAT) and four files on Windows 95 (SYSTEM.DAT, USER.DAT, SYSTEM.DA0, and USER.DA0).
These files are found on the \Windows folder and are attributed as read-only, system, and
hidden.
Most people don’t know of them until one sad day when they see the error message that the System Registry is corrupted and they should replace it with a backup. Unfortunately, they won’t have a back up of it. If they did, the steps to recover these files from DOS involve using a program that many users don’t know how to use ATTRIB.EXE, and involve some simple DOS commands for changing directories and copying.
The bottom line, most people don’t have backups of the registry and would not be able to use the backups if they had them. The ERU program will, however, make the backup and restore effortless.
Installing ERU.EXE
It is important to find and install this utility before you discard your Windows 95 CD-ROM. This utility works fine on the Windows 98 operating system but Microsoft did not continue to distribute the program on the Windows 98 CD.Step 1. From Windows Explorer go to the Windows 95 CD directory named OTHER/MISC/.
Step 2. Drag and copy the folder named ERU to your Drive C:/ (or other hard drive of choice).
Step 3. Double click your way into this new ERU folder on your hard drive.
Step 4. In that directory, locate the file ERU.INF.
Step 5. Right-click on the ERU.INF file and click INSTALL on the menu that pops up. Install takes two seconds.
Step 6. Make a shortcut to ERU.EXE on your desktop or Start Menu.
Backing up the registry with ERU.EXE
Do this every time before installing new software and you will never be sorry. If you
make changes and don’t want to redo all the work, run ERD and save it with a new
date.
Step 1. Double click on the ERU shortcut. It will ask you to use a "Drive A:" or "Other Directory."
Step 2. You must choose "Other Directory" (your registry will be too big for a floppy).
Step 3. Click on Next. The dialog will offer C:\ERD as an option. (Note, the prompt reads ERD not ERU).
Step 4. To the directory field "C:\ERD" add a "\" and the current date. I use the form MMMDD, as in JUL25, for the date. It would then read "C:\ERD\JUL25." Then click Next.
Step 5. Accept the list of files and click Next. Your registry files are backed up in that directory.
Do this every time before installing new software and you will never be sorry. I do this every couple of days because any changes you make after the backup will be absent from the backup. So, if you make great changes and don’t want to redo all the work, make another ERD copy of the registry with a new date. Every few weeks, delete the folders that have very old dates. You won’t need them if you have more recent good backups.
Restoring your registry from the backup
The registry can become corrupted from mis-behaving software you installed. If you
can’t boot to Windows or you get an intolerable number of hang ups, your system
registry is most likely corrupted. Without a backup of the registry, the only
way to recover from the inability to boot to Windows has been to reinstall Windows, and in
some case even wipe out the present Windows directory, reinstall Windows fresh, and then
reinstall all your software ( NOT a good choice for spending a weekend or more of your
time!). But now you have backups.
You can restore the registry to its last backed up and working state by running ERD.EXE from DOS. Everything will be done for you automatically. You will then be able to boot Windows 95/98 in exactly the state that existed before the disaster. In a nutshell: To recover a working registry, you need only have made a backup of a working registry, boot to DOS, change to the directory where you put the backups, and type the ERD.EXE.
Step 1. Turn on your computer and watch carefully for the screen message "Starting Windows 95…"
Step 2. At that moment, immediately(!), hit the F8 key and you will get the Windows boot up menu display.
Step 3. Choose the option that reads "Command Prompt Only" and hit [enter].
Step 4. From the C:\> prompt type "CD C:\ERD\JUL25" and hit [enter] (Note: type the date of the last backup instead of JUL25)!
Step 5. From that directory type ERD and hit [enter].
Step 6. Just wait about half a minute. Be happy. ERD is finding SYSTEM.DA*, USER.DA*, SYSTEM.INI, WIN.INI, CONFIG.SYS, AUTOEXEC.BAT and anything else you choose to add, and putting them back in the Windows and root folders (changing hidden, read only, and system attributes for you automatically so you don’t even have to know what those words mean).
Step 7. Reboot. Windows will start up to its last saved state unless other critical files have been deleted or replaced since that time.
Conclusion
This will save you in about 95% of the cases. In a small percentage of the time, say
5%, Windows will still be unable to start after this restoration of system files. This is
most often due to the deletion of some critical files or the change in version of some
critical files Windows needs to find. Fortunately, this is rare. You will most likely be
able to boot to Windows and resume work.
Remember, any changes you made, including installation of any software, after your backup, will have to be reinstalled to insure it will work correctly. But also note, if something you recently installed messed up your registry, isolate the program and don’t reinstall it again! So, make frequent backups with ERU and reduce the work you will have to do to get back to your desired state. Finally, making a complete tape backup of your system on a regular basis is an important way to protect the rest of your system.
Copyright © 1998 by Stephen Lankton.
"Go Inside" is a David Boles Trademark