This step-by-step article describes how to back up, edit,
and restore the registry in Windows NT 4.0. Microsoft recommends that before
you edit the registry, you back up the registry and understand how to restore
it if a problem occurs.
How to Back Up the Registry
Before you edit the registry, export the keys in the registry
that you plan to edit, or back up the whole registry. If a problem occurs, you
can then follow the steps in the How to Restore
section of this article to restore the registry to its
How to Export Registry Keys
You can follow these steps to export a registry key before you
edit it. NOTE
: Do not follow these steps to export a whole registry hive (for
example, the HKEY_CURRENT_USER
hive). If you must back up whole registry hives, back up the
whole registry instead.
- Click Start, and then click Run.
- In the Open box, type regedt32, and then click OK.
- Locate and then click the key that contains the values that
you plan to edit.
- On the Registry menu, click Save Key.
- In the Save in box, select a location in
which to save the .reg file, type a file name in the File name
box, and then click Save.
How to Back Up the Whole Registry
To back up the whole registry, use the Windows NT Backup tool
(Ntbackup.exe) and use the option to back up the registry. Or, run the
additional information about using the Rdisk tool to update your repair
information, click the article number below to view the article in the
Microsoft Knowledge Base:
Description of Windows NT Emergency Repair Disk
: You must have a supported tape drive to use Windows NT Backup to
back up the registry. If you do not have a supported tape drive, use Rdisk.
When you run the rdisk /s
command to update your repair
information, compressed copies of the registry files are placed in the
%SystemRoot%\Repair folder. If you cannot start Windows NT after you edit the
registry, you can manually replace the registry files by expanding the copies
in the %SystemRoot%\Repair folder.
How to Edit the Registry
To edit the registry, Microsoft recommends that you follow the
steps in the Microsoft documentation only. If possible, use the Windows user
interface instead of directly editing the registry.
Editor incorrectly can cause serious problems that may require that you
reinstall your operating system. Microsoft cannot guarantee that problems that
result from incorrectly using Registry Editor can be solved. Use Registry
Editor at your own risk.
For more information about editing the
registry, follow these steps in Registry Editor (Regedt32.exe):
- On the Help menu, click Contents.
- Click the Contents tab.
- Double-click the topic that you want to read.
How to Restore the Registry
How to Restore Registry Keys
- Click Start, and then click Run.
- Type regedt32, and then click OK.
- On the Registry menu, click Restore.
- Select the .reg file that you saved in the
How to Backup the Registry section
of this article, and then click Open.
- Click Yes to continue.
How to Restore the Whole Registry
To restore the whole registry, restore a registry backup by using
the Windows NT Backup utility.NOTE
: If you ran the rdisk /s
command to update the
repair information, updated, compressed copies of the registry files are
located in the %SystemRoot%\Repair folder. If you cannot start Windows NT after
you edit the registry, you can manually replace the registry files in the
%SystemRoot%\System32\Config folder by expanding the compressed copies in the
%SystemRoot%\Repair folder. You must start MS-DOS (if the drive uses the FAT
file system) or perform a parallel installation of Windows NT (if the drive
uses the NTFS file system) to do this.
How RDISK.EXE Updates Repair Information
RDISK /S and RDISK /S- Options in Windows NT