STOP C0000218 Registry failure in WINXP

You need to 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. When you
have finished this procedure, a registry is created that you can use
to start Windows XP. This registry was created and saved during the
initial setup of Windows XP. Therefore any changes and settings that
occurred after the Setup program was finished are lost.

To complete part one, follow these steps:
1.Insert the Windows XP startup disk into the floppy disk drive, or
insert the Windows XP CD-ROM into the CD-ROM drive, and then restart
the computer.
Click to select any options that are required to start the computer
from the CD-ROM drive if you are prompted to do so.
2.When the "Welcome to Setup" screen appears, press R to start the
Recovery Console.
3.If you have a dual-boot or multiple-boot computer, select the
installation that you want to access from the Recovery Console.
4.When you are prompted to do so, type the Administrator password. If
the administrator password is blank, just press ENTER.
5.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
6.Type exit to quit Recovery Console. Your computer will restart.
Note This procedure assumes that Windows XP is installed to the C:
\Windows folder. Make sure to change C:\Windows to the appropriate
windows_folder if it is a different location.

If you have access to another computer, to save time, you can copy the
text in step five, and then create a text file called
"Regcopy1.txt" (for example). To use this file, run the following
command when you start in Recovery Console:
batch regcopy1.txt
With the batch command in Recovery Console, you can process all the
commands in a text file sequentially. When you use the batch command,
you do not have to manually type as many commands.