You can recover to a system of windows XP if you had some corruption in the registries. If an OEM installed operating system then the following procedure should not be adopted. When you wish to start the windows XP operating system then you might get error such as windows XP could not start as some file was missing or corrupt. The file can be \WINDOWS\SYSTEM32\CONFIG\SYSTEM or WINDOWS\SYSTEM32\CONFIG\SOFTWARE. You can also have the messages

Stop: c0000218 {Registry File Failure} The registry cannot load the hive (file): \SystemRoot\System32\Config\SOFTWARE or its log or alternate

System error: Lsass.exe
When you try to update the password and the return status shows that the value given is not the correct one.

Process to manually recover from a corrupted registry

You can use the recovery console and system restore for this purpose. With the help of following the right procedure you would be able to bring your system back to the state which would be very close to the state before problem occurred. The following procedure is for those systems on which NTBackup had been run and the system state backup was completed,

Start the recovery console and create one temporary folder. You must back up the existing files of the registry to some new location and then delete the files present at the existing location. You must then copy the files of the registry from repair folder into the folder of System32/Config. Once you are done with this procedure a registry would be created that can be used for starting your windows XP. During the initial setup this registry was created and was saved too and this is why if any change or settings were done after the setup program then they would be lost.

First of all insert the startup disk of Windows XP in the floppy disk drive or insert the CD into the CD drive and restart your computer. As the welcome to setup screen pops, you must press R to get to the recovery console. Give in the administrator password. In the command prompt of the recovery console you must type the following lines and enter after each of the 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

After these lines type exit and your computer will restart. The above lines should be written if your windows XP operating system is installed on C:\Windows folder. If you have installed the operating system on some other locations then you must change the location and change c:\windows to your own windows_folder. If you have access to some other computer then you can easily copy this text in five steps for the sake of saving time. You can then create, for instance, Regcopy1.txt file. This file can run through the command batch regcopy1.txt.

After this you must click on the start button and then on All programs. Click on accessories then system tools and then click on system restore. After this you must click on restore to a previous RestorePoint.