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Vic's Registry RoundUp
~~Vic Ferri, Win Tips and Tricks

Backing Up and Restoring the Windows Registry

It is always wise to back up your registry before making any changes to it.  This applies, especially, to the novice or to anyone who isn't certain of the effects the changes being made will have on the operating system.  One little mistake with reg editing can take down Windows to the point of not being able to boot.  Backing up the registry before editing makes any errors you make repairable and thus registry editing becomes safe, rather than risky.

There are several ways to backup the registry. However in this article, I will focus on the auto and manual methods built into Windows.

Windows 95
 
Auto Backup

The Windows 95 registry is made up of two files, SYSTEM.DAT and USER.DAT , located in your Windows folder. These registry files are backed up automatically after every successful start of Windows. The backed up files are named SYSTEM.DA0 and USER.DA0 and are also located in your Windows directory.  Should Windows fail to start due to a registry error, you will be prompted to restart your computer to restore your registry. During the reboot, the backed up da0 files are used to restore your registry to the previous state it was before the error. This method, however, is by no means fail proof. 

It is quite common to end up with corrupted dat and da0 files. This can easily happen when restarting after a bad regedit.  Therefore, it is wise to manually back up the registry before making any system changes.

Windows 95 also contains an additional system.dat backup file called System.1st located in your root drive (usually c:) This represents your registry as it was when you first installed Windows. If your registry becomes so corrupted that you can not recover it, you can always try replacing c:\windows\system.dat with c:\system.1st and  then renaming system1st, system.dat. In my experience, however, this rarely works and it's usually easier to just do a reinstall. The reason is that System1st is very bare bones; it doesn't include all the many programs you may have installed after installing Windows.

Manual Backup 

In Windows 95, manually backing up the Registry is a simple matter of copying system.dat and user.dat and saving them to a safe location (personally, I back up my registry files to a Windows folder named Regbak).

Note, that by default, dat files are hidden, so you must have Show All Files enabled to find these files.  To do that:  In any folder, click View>Options>View and then check Show All Files. 

Restoring

Should the registry become corrupt, you can use your backed up files to restore it.  To do that, you would restart your computer in native DOS and at the C:\> prompt, type the following commands, pressing Enter after each one (in this example, it is assumed your backed up reg files are in C:\Windows\Regbak)

attrib -h -s -r c:\windows\system.dat
attrib -h -s -r c:\windows\user.dat
attrib -h -s -r c:\windows\regbak\*.dat
copy c:\windows\regbak\system.dat c:\windows\system.dat /v /y
copy c:\windows\regbak\user.dat c:\windows\user.dat /v /y

Once the files are copied, reboot. 

Scanreg in Windows 95 

Scanreg from Windows 98\98se can also be used to back up\ restore the registry in Windows 95. 

Simply copy the 98 files, scanregw.exe and scanreg.exe to your 95 hardrive. Both are self executing files.  Double click scanregw.exe and your registry will be scanned and then you will be given the option to back it up.

The first backup you make will be placed in c:\windows\sysbckup in a cab file named rb000.cab.  See the details for scanreg in the Windows 98 section for more details.

Windows 98\98se

Registry Checker - Auto Backup & Restore

The Registry Checker (aka ScanReg) is a built-in Registry backup and restore tool and comes in two versions -  scanregw.exe which runs only in Windows and  scanreg.exe which runs only in DOS. 
 
SCANREGW.EXE
 
The Windows Registry checker (scanregw.exe) scans your Windows 98 Registry for errors once a day. If there are no errors, the Registry Checker automatically backs up the Registry. If an error is found, the Registry Checker automatically restores the most recent copy of the Registry. The Registry Checker keeps, by default, five backup copies of the Registry and stores them as .CAB files in C:\Windows\Sysbckup. The first backup is called RB000.CAB, the second RB001.CAB and so on.  You can increase the number of backups created by editing scanreg.ini and changing the MaxBackupCopies entry.
 
SCANREG

To back up your registry in DOS using scanreg, restart your computer in DOS mode and at the DOS prompt type:  scanreg /backup  and press Enter.  Scanreg will back up your registry and then return a DOS prompt. 

Restoring

In most cases, you will be restoring the Registry in DOS mode using scanreg.exe.

Start Windows in native DOS mode - the easy way to do this is to simply choose Restart in MS-DOS Mode from the Shutdown menu or if you can't get into Windows, reboot. press F8 at the startup screen and then choose Command Prompt Only from the 98 Boot Menu.

At the prompt, type scanreg /restore and follow the prompts.

You'll see a box  listing each backup, the date each was created, as well as information that tells you whether the backup has been used to successfully start the operating system. All you need to do is select a backup and press Enter.

To see all your scanreg options, type scanreg /? at the DOS prompt. 
 
Manual Backup & Restore
 
You can also use the Registry Checker to  backup the registry whenever you choose.  Click Start>Run and type in scanregw.exe to start the Registry Checker. After scanning the Registry for errors, you will be asked if you would like to make another backup of the Registry.  Click Yes.
 
As well you can manually backup the 98 Registry by copying system.dat and user.dat which are in your Windows folder, to a safe place (same way as in Windows 95)  This is actually the easiest way to backup the registry.  It's just a matter of copying and pasting the two files to a new folder.  Note that these files are hidden by default.  If  you can't find them, open any folder and click View>Folder Options>View tab and choose Show All Files.

To restore the registry from your own backed up system.dat and user.dat, follow the instructions presented for Windows 95. 
 
Automating the Manual Backup & Restore of the Win9x Registry

The  entire manual backup and restore of the Windows 95\98\98se Registry can be simplified with a couple of bat files that when clicked will automatically backup or restore your Registry.  Go here for full instructions.
http://www.angelfire.com/on3/vxdoin2/RegBak.html

Windows Me

In Windows Me, the registry files are System.dat, User.dat and Classes.dat. These can be backed up manually but to restore you need Ms-Dos access.  Use the same instructions and commands as described in the Windows 95 section.

Scanreg is also part of Windows Me and like Windows 98, the registry is backed up automatically at startup. However, the  main restore feature of Me is System Restore which automatically monitors and records changes made to the essential Windows system files including the registry.  If your system becomes corrupt, System Restore allows you to undo (or "roll back") a change that caused instability in your system.

To use, Click Start>Programs>Accessories>System Tools, and then click System Restore.  

Click Restore my computer to an earlier time and click Next.  

In the calendar that appears choose which Restore Point to roll your system back to and click Next.  

You will then be prompted to close all programs and reboot. On restart, a confirmation screen appears. Click OK to continue using your computer.

The next time you start System Restore, you will see a third option, Undo my last restoration. This is available in the event that the Restore Point you rolled back to does not correct the original problem that you were having and so you can easily get back to the point in time that you started troubleshooting.
For more info on System Restore, click here.

Note that System Restore does not have a very good track record when it comes to reliability. There have been many reports of disaster using System Restore so use at your own risk.  Personally, I prefer to manually back up the registry files as I have always done since Windows 95.

Windows 2000

Automatically backing up the registry changed with systems built on the NT kernel platform - Windows NT4 and above.
Instead of automatic reg backups, Windows 2000 ships with the the  Backup utility for backing up the Registry. It's located in the the System Tools menu. When you start it, you'll see an item called System State, under My Computer. The System State is a collection of system specific data and as you will see includes the Registry.  Simply select Registry and click the Start Backup button.

Another method of backing up the Registry in Windows 2000 (and NT/XP) is by rebooting your system and when you see the Please Select the Operating System to Start message, press F8 and then use arrow keys to select the Last Known Good Configuration option and press Enter. This instantly restores the most recent copy of the Registry.  You can also use this method in Windows NT.

Restore

To restore the Win2K Registry, start the Backup utility, select the Restore tab, choose the backup media, and then select the System State check box. Note that this not only restores the Registry, but all of the System State data.

The real registry files (known as hives) reside in \WINNT\SYSTEM32\CONFIG and are named  DEFAULT, SAM, SECURITY, SOFTWARE, and SYSTEM (no extensions)  but they can't be backed up by simply copying and pasting -  you will get a file in use error message if you try.  However, there are utilities you can use to make the backup possible. My personal favorite is ERUNT.  Just do a search on the net for more info.  Of course, if you have a dual boot fat system such as Windows 9x and Windows 2000, you can always copy the 2000 registry files from your Windows 9x partition where you have normal access to the files and folders on your 2000 system.   It also  makes restoring the registry a simple copy and paste operation. Just let Windows overwrite the existing files. And you can also always use the copy command in Ms-Dos or the Recovery console to do backups and restores. See the copy method for Windows 95 for an idea on how to use it.

Windows XP

Like Windows 2000, the registry is not automatically backed up in XP and the registry files are also named DEFAULT, SAM, SECURITY, SOFTWARE, and SYSTEM and cannot be backed up in Windows by copy paste operations.
They are located in \WINDOWS\SYSTEM32\CONFIG (a quick way to access the folder is  by entering CONFIG in the Run box) The same manual backup possibilites as in 2000 apply to XP.  You can use a utiltiy like ERUNT or copy manually if you have a Fat dual or multi boot system where you have access to your other system partitions.  When doing manual backups, make a point to keep them current. Backup regularly.
Windows XP's main backup feature is System Restore which backs up and restores your whole system.  However, like the Windows Me Restore utility, it does not appear to be overly reliable - there have been quite a few reports of it failing to restore.  Having said that, if you would like to use it, you can access it by clicking Start>All Programs>Accessories>System Tools>System Restore.  Here you can set Restore Points or do Restores to an earlier time.  Just follow the instructions which are very easy to follow. If you need more information on System Restore, click Start>Help and Support and type SYSTEM RESTORE in the Search box.

And also like Windows 2000, you can restore to the last known good configuration if you run into problems.
This refers to the last settings you used that had no problems.  To do such a restore, restart your computer and tap F8 until you see the Windows Advanced Options menu.  Here you will see where you can select the Last Known Good Configuration by using the arrow keys to select and pressing Enter to initiate the restore.

Vic Ferri owns the very popular WinTips and Tricks and Registry Answers.  Subscribe to either and receive free Windows and Registry Tips.  He is also in charge of the Printing Tips  pages at Linda's Computer Stop.  Vic has also created a program which allows you to Lock & Hide desktop folders in Windows 9X/ME.  Read more and get the free demo here.  And, he now offers a service to convert PowerPoint presentations to .exe files which can be viewed on computers which do not have PowerPoint installed.