Playing with the Windows Registry in a DOS environment - China DOS Union Forum

Playing with Windows Registry in DOS Environment
By/Red Maple Forest

　　The Registry Editor can not only run and be used under Windows, but also run in MS-DOS real mode. Sometimes when the registry is damaged and Windows cannot be started, we have to repair or modify the registry in DOS mode. The actual physical files of the registry are System.dat and User.dat, that is to say, the data in the registry is saved in these two files.

　　Exporting the Registry

　　This command can realize the backup of the registry file.

　　Command format: Regedit /L:system /R:user /E filename.reg Regpath

　　Parameter meanings:

　　/L: system specifies the path where the System.dat file is located.

　　/R: user specifies the path where the User.dat file is located.

　　/E: This parameter specifies that the Registry Editor is to perform the operation of exporting the registry. After this parameter, leave a space and enter the file name for exporting the registry.

　　Regpath: used to specify which branch of the registry is to be exported. If not specified, all registry branches will be exported.

　　If you intend to export all the branches under the HKEY_CLASSER_ROOT root key saved in C:\Windows\System.dat and saved in C:\Windows\Profiles\User.dat to file.reg, you can execute the following command: Regedit /L:C:\Windows\ /R:C:\Windows\Profiles\ /e file1.reg HKEY_CLASSER_ROOT

　　Importing the Registry

　　Command format: Regedit /L:system /R:user file.reg

　　Parameter meanings:

　　/L: system specifies the path where the System.dat file is located.

　　/R: user specifies the path where the User.dat file is located.

　　Rebuilding the Registry

　　Rebuilding the registry means re-establishing the System.dat and User.dat files.

　　Command format: Regedit /L:system /R:user /C file.reg

　　Parameter meanings:

　　/L: system specifies the path where the System.dat file is located.

　　/R: user specifies the path where the User.dat file is located.

　　/C: This parameter will tell the Registry Editor to re-establish the registry with the content in the specified.reg file.

　　If you want to re-establish the entire registry with the content in the file.reg file and save it to C:\Windows\System.dat and C:\Windows\Profiles\User.dat, you can execute the command: Regedit /L:C:\Windows\ /R:C:\Windows\Profiles\ /C file1.reg

　　Deleting Registry Branches

　　This command can delete a subkey branch in the registry.

　　The command format is: Regedit /L:system /R:user /D Regpath

　　Parameter meanings:

　　/L: system specifies the path where the System.dat file is located.

　　/R: user specifies the path where the User.dat file is located.

　　/C: This parameter tells the Registry Editor to delete the registry subkey branch specified by Regpath.

　　Restoring the Registry

　　Scanreg.exe can check, backup, restore, and repair the registry. This command is stored in the "Windows\Command" directory.

　　Command format: Scanreg

　　Parameter meanings:

　　The /backup parameter is to backup the registry and related configuration files. These files are the four files System.dat, User.dat, Win.ini, and System.ini under the \windows directory respectively. Compress these files into a rb-?.cab file and store it in the \windows\sysbckup directory. Using this command multiple times will generate multiple CAB files, generally starting from 000. The system default maximum number of backups is 5. You can modify the maximum number of backups in the \Windows\scanreg.ini file by modifying the value of "maxbackupcopies=?".

　　The /restore parameter is to select a backup to restore the registry. This command cannot be executed in the Windows 98 environment. It must be shut down and then restarted to enter the pure DOS mode to run.

　　The /fix parameter is to repair the damaged registry. This command can also only be run in DOS mode.

　　The /comment="" parameter is to add some detailed comments to the CAB file when backing up the registry.

　　To restore the damaged registry file, you can use the Scanreg command to repair it. The method is: first enter the DOS system operating environment, and then execute the following command: Scanreg /Restore

　　At this time, the system will prompt the registry backup situation, including the CAB file name and backup time, etc. The user can select the CAB file to be restored for recovery.

　　If you want to view all backup files and the parts related to backup, you can execute the command: Scanreg /restore /comment

　　If there is a problem with the registry, you can use Scanreg to repair it. The command is: Scanreg /fix.

——Extracted from: China Computer Education News

Floor1　Lydong	Posted 2002-10-25 00:00
元老会员　Posts 407　Credits 1,468　From 广州
Playing with Windows Registry in DOS Environment By/Red Maple Forest 　　The Registry Editor can not only run and be used under Windows, but also run in MS-DOS real mode. Sometimes when the registry is damaged and Windows cannot be started, we have to repair or modify the registry in DOS mode. The actual physical files of the registry are System.dat and User.dat, that is to say, the data in the registry is saved in these two files. 　　Exporting the Registry 　　This command can realize the backup of the registry file. 　　Command format: Regedit /L:system /R:user /E filename.reg Regpath 　　Parameter meanings: 　　/L: system specifies the path where the System.dat file is located. 　　/R: user specifies the path where the User.dat file is located. 　　/E: This parameter specifies that the Registry Editor is to perform the operation of exporting the registry. After this parameter, leave a space and enter the file name for exporting the registry. 　　Regpath: used to specify which branch of the registry is to be exported. If not specified, all registry branches will be exported. 　　If you intend to export all the branches under the HKEY_CLASSER_ROOT root key saved in C:\Windows\System.dat and saved in C:\Windows\Profiles\User.dat to file.reg, you can execute the following command: Regedit /L:C:\Windows\ /R:C:\Windows\Profiles\ /e file1.reg HKEY_CLASSER_ROOT 　　Importing the Registry 　　Command format: Regedit /L:system /R:user file.reg 　　Parameter meanings: 　　/L: system specifies the path where the System.dat file is located. 　　/R: user specifies the path where the User.dat file is located. 　　Rebuilding the Registry 　　Rebuilding the registry means re-establishing the System.dat and User.dat files. 　　Command format: Regedit /L:system /R:user /C file.reg 　　Parameter meanings: 　　/L: system specifies the path where the System.dat file is located. 　　/R: user specifies the path where the User.dat file is located. 　　/C: This parameter will tell the Registry Editor to re-establish the registry with the content in the specified.reg file. 　　If you want to re-establish the entire registry with the content in the file.reg file and save it to C:\Windows\System.dat and C:\Windows\Profiles\User.dat, you can execute the command: Regedit /L:C:\Windows\ /R:C:\Windows\Profiles\ /C file1.reg 　　Deleting Registry Branches 　　This command can delete a subkey branch in the registry. 　　The command format is: Regedit /L:system /R:user /D Regpath 　　Parameter meanings: 　　/L: system specifies the path where the System.dat file is located. 　　/R: user specifies the path where the User.dat file is located. 　　/C: This parameter tells the Registry Editor to delete the registry subkey branch specified by Regpath. 　　Restoring the Registry 　　Scanreg.exe can check, backup, restore, and repair the registry. This command is stored in the "Windows\Command" directory. 　　Command format: Scanreg 　　Parameter meanings: 　　The /backup parameter is to backup the registry and related configuration files. These files are the four files System.dat, User.dat, Win.ini, and System.ini under the \windows directory respectively. Compress these files into a rb-?.cab file and store it in the \windows\sysbckup directory. Using this command multiple times will generate multiple CAB files, generally starting from 000. The system default maximum number of backups is 5. You can modify the maximum number of backups in the \Windows\scanreg.ini file by modifying the value of "maxbackupcopies=?". 　　The /restore parameter is to select a backup to restore the registry. This command cannot be executed in the Windows 98 environment. It must be shut down and then restarted to enter the pure DOS mode to run. 　　The /fix parameter is to repair the damaged registry. This command can also only be run in DOS mode. 　　The /comment="" parameter is to add some detailed comments to the CAB file when backing up the registry. 　　To restore the damaged registry file, you can use the Scanreg command to repair it. The method is: first enter the DOS system operating environment, and then execute the following command: Scanreg /Restore 　　At this time, the system will prompt the registry backup situation, including the CAB file name and backup time, etc. The user can select the CAB file to be restored for recovery. 　　If you want to view all backup files and the parts related to backup, you can execute the command: Scanreg /restore /comment 　　If there is a problem with the registry, you can use Scanreg to repair it. The command is: Scanreg /fix. ——Extracted from: China Computer Education News

Floor2　醉公子	Posted 2003-06-12 00:00
初级用户　Posts 57　Credits 333
Can I back up the registry using DOS under Windows 2000?

Floor3　iversonhe	Posted 2003-06-13 00:00
初级用户　Posts 6　Credits 132
Where are the user.dat and system.dat in XP? I want to know the detailed path~