Registry DataBase : Backup | ||||||||||||||||||||||||||||||||
Windows 95 - Windows 98/ME - Windows NT 4.0 - Backup by
hand (NT) Automatic backup (NT) - Backup on several diskettes (NT) |
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Top | Windows 95 | |||||||||||||||||||||||||||||||
The Windows 95/98/ME
registry database is made of 2, 3 or 4 files located in
the Windows folder :
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Those files have the 3 following
attributes :
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Windows 98/ME
include a backup utility but in Windows
95, the registry must be saved by hand. To do so,
you must remove those attributes to be able to access
those files :
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There are 2 other interesting utilities on Windows
95's original CD in the folder Other\Misc
: CfgBack.exe and Eru.exe. CfgBack.exe makes a backup of the configuration stored in Windows's folder, called RegBackX.rbk, where X identifies the backup copy number. This file contains compressed User.dat and System.dat. A file called RegBack.ini is also used to log backup dates and names. The Eru.exe (Emergency Recovery Utility) enables saving vital files to diskette (if it is still possible) or to disk. The following files may be saved by Eru.exe : Config.sys, AutoExec.bat, Win.ini, System.ini, Protocol.ini, User.dat, System.dat, IO.sys, Command.com, MsDos.sys. If there is not enough room on the diskette, make separate backups by ticking the files to be saved in Eru.exe's dialog box. |
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Top | Windows 98/ME | |||||||||||||||||||||||||||||||
Automatic backup There is an automatic backup procedure in Windows 98/ME based on 5 backup sets compressed in .cab files stored in %WinDir%\Sysbckup. A backup is made every day when the machine is started for the first time. No other backup will be made if the machine is restarted the same day or if it is not turned off for several days. Backup copies are made of Rb00X.cab files where X identifies the backup copy number. The corresponding applications are ScanReg (DOS) and ScanRegW (Windows). Backup by hand Run ScanRegW in Windows. First, the system checks the registry. Then it displays a dialog box called Registry check result whiche the following message : The system has already made a backup of the registry today. Do you want to make another one ? Click on Yes. Restore a previous copy of the registry Start in MS-DOS mode, type ScanReg /restore and choose the backup to restore. Restart Windows. |
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Top | Windows NT 4.0 | |||||||||||||||||||||||||||||||
See the hives section for more
information. The Windows NT registry database is made of 6 files located in %SystemRoot% \System32 \Config, except for Ntuser.dat located in %USERPROFILE%. The Userdiff file is for compatibility with previous versions of Windows. |
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If NT is installed on a FAT
partition You can use the same method as in Windows 95 to backup the registry (backup by hand). |
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If NT is installed on a
NTFS partition Unless you have special tools, sorts of DOS NTFS drivers, it is not possible to access an NTFS partition when booting with a diskette because NTFS partitions need mounting, more or less as in Unix. There are 2 methods for saving the Windows NT registry : by hand (whole registry) or automatic (hardware configuration only). You may prefer to install a 2nd copy of NT from which you will be able to boot to restore your main system's registry. |
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If you have the Resource
Kit MV utility Uncompress you registry backup and have this batch launched at startup :
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Top | Backup by hand | |||||||||||||||||||||||||||||||
Registry
backup |
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Registry
restore |
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Top | Automatic backup | |||||||||||||||||||||||||||||||
Automatic backup handles registry
hardware configuration. It can be restored at Windows
NT startup, when the system displays the message
Press space... It can not be configured
by the user because Windows NT does it
by storing 3 hardware configurations in HKLM \System
\CurrentControlSet : ControlSet001 ControlSet002 ControlSet003 Numbers will be incremented (ControlSet00X) according to the various versions of the registry. The HKLM \CurrentControlSet \Select subkey indicates how to use them : |
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Key :
HKLM \CurrentControlSet \Select Entry : Current System : NT, 2K Type : REG_DWORD Value : Backup copy number |
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Active configuration. Same as CurrentControlSet. | ||||||||||||||||||||||||||||||||
Key :
HKLM \CurrentControlSet \Select Entry : Default System : NT, 2K Type : REG_DWORD Value : Backup copy number |
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Configuration to be used at next startup, except if the user makes a change. | ||||||||||||||||||||||||||||||||
Key :
HKLM \CurrentControlSet \Select Entry : Failed System : NT, 2K Type : REG_DWORD Value : Backup copy number |
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This configuration failed and was replaced with LastKnownGood the last time the machine was started. | ||||||||||||||||||||||||||||||||
Key :
HKLM \CurrentControlSet \Select Entry : LastKnownGood System : NT, 2K Type : REG_DWORD Value : Backup copy number |
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Last known good configuration. This entry
will only be changed if startup fails. The HKLM \SYSTEM \Clone key is built during startup and contains a temporary copy of the control set used to boot. When Winlogon has reported that everything went fine, it will become LastKnownGood. |
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Top | Backup on several diskettes | |||||||||||||||||||||||||||||||
If your ERD is full because
the registry is too big :
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© Franck Kiechel 2000-2001 |