This is how to recover a system that does not start because of corruption in the registry. This procedure does not guarantee full recovery of the system to a previous state; however, you should be able to recover data when you use this procedure.
This will not work with a computer that has an OEM-installed operating system.
The procedure that this article describes uses Recovery Console and System Restore. This article also lists all the required steps in specific order to make sure that the process is fully completed. When you finish this procedure, the system returns to a state very close to the state before the problem occurred.
Start the Recovery Console, create a temporary folder, back up the existing registry files to a new location, delete the registry files at their existing location, and then copy the registry files from the repair folder to the System32\Config folder.
Insert the install O/S disk and then restart the computer.
When the “Welcome to Setup” screen appears, press R to start the Recovery Console.
When you are prompted to do so, type the Administrator password. If the administrator password is blank, just press ENTER.
At the Recovery Console command prompt, type the following lines, pressing ENTER after you type each line:
md tmp
copy c:\windows\system32\config\system c:\windows\tmp\system.bak
copy c:\windows\system32\config\software c:\windows\tmp\software.bak
copy c:\windows\system32\config\sam c:\windows\tmp\sam.bak
copy c:\windows\system32\config\security c:\windows\tmp\security.bak
copy c:\windows\system32\config\default c:\windows\tmp\default.bak
delete c:\windows\system32\config\system
delete c:\windows\system32\config\software
delete c:\windows\system32\config\sam
delete c:\windows\system32\config\security
delete c:\windows\system32\config\default
copy c:\windows\repair\system c:\windows\system32\config\system
copy c:\windows\repair\software c:\windows\system32\config\software
copy c:\windows\repair\sam c:\windows\system32\config\sam
copy c:\windows\repair\security c:\windows\system32\config\security
copy c:\windows\repair\default c:\windows\system32\config\default
Type exit to quit Recovery Console.
Your computer will restart.
During the boot screen Press the F8 key.
On a computer that is configured to start to multiple operating systems, you can press F8 when you see the Startup menu.
Use the arrow keys to select the Safe mode option, and then press ENTER.
select the installation that you want to access, and then press ENTER.
Start Windows Explorer.
On the Tools menu, click Folder options.
Click the View tab.
Under Hidden files and folders, click to select Show hidden files and folders, and then click to clear the Hide protected operating system files (Recommended) check box.
Click Yes when the dialog box that confirms that you want to display these files appears.
Open the System Volume Information folder. This folder is unavailable and appears dimmed because it is set as a super-hidden folder.
Note This folder contains one or more _restore {GUID} folders such as “_restore{87BD3667-3246-476B-923F-F86E30B3E7F8}”.
Open a folder that was not created at the current time. You may have to click Details on the View menu to see when these folders were created. There may be one or more folders starting with “RPx under this folder. These are restore points.
Open one of these folders to locate a Snapshot subfolder. The following path is an example of a folder path to the Snapshot folder:
C:\System Volume Information\_restore{D86480E3-73EF-47BC-A0EB-A81BE6EE3ED8}\RP1\Snapshot
From the Snapshot folder, copy the following files to the C:\Windows\Tmp folder: _REGISTRY_USER_.DEFAULT
_REGISTRY_MACHINE_SECURITY
_REGISTRY_MACHINE_SOFTWARE
_REGISTRY_MACHINE_SYSTEM
_REGISTRY_MACHINE_SAM
Rename the files in the C:\Windows\Tmp folder as follows:
Rename _REGISTRY_USER_.DEFAULT to DEFAULT
Rename _REGISTRY_MACHINE_SECURITY to SECURITY
Rename _REGISTRY_MACHINE_SOFTWARE to SOFTWARE
Rename _REGISTRY_MACHINE_SYSTEM to SYSTEM
Rename _REGISTRY_MACHINE_SAM to SAM
These files are the backed up registry files from System Restore. Because you used the registry file that the Setup program created, this registry does not know that these restore points exist and are available. A new folder is created with a new GUID under System Volume Information and a restore point is created that includes a copy of the registry files that were copied during part one.
Delete the existing registry files, and then copy the System Restore Registry files to the C:\Windows\System32\Config folder:
Start Recovery Console.
At the command prompt, type the following lines, pressing ENTER after you type each line:
del c:\windows\system32\config\sam
del c:\windows\system32\config\security
del c:\windows\system32\config\software
del c:\windows\system32\config\default
del c:\windows\system32\config\system
copy c:\windows\tmp\software c:\windows\system32\config\software
copy c:\windows\tmp\system c:\windows\system32\config\system
copy c:\windows\tmp\sam c:\windows\system32\config\sam
copy c:\windows\tmp\security c:\windows\system32\config\security
copy c:\windows\tmp\default c:\windows\system32\config\default
Type exit to quit Recovery Console.
Your computer restarts.
Click Start, and then click All Programs.
Click Accessories, and then click System Tools.
Click System Restore, and then click Restore to a previous RestorePoint.