Repairing System32 in Windows XP
1. If possible, do an Automated System Recovery by clicking on 'Start' and running the mouse pointer over 'All Programs,' 'Accessories' and 'System Tools' and clicking on 'Backup.' If 'Backup' is not on the 'System Tools' list, you probably can't do an automated system recovery.
2. When the backup utility starts, click on 'Advanced Mode.'

3. Click on 'Tools' and then 'ASR Wizard.'
4. Follow the instructions in the ASR Wizard.
5. Save the backup to a floppy disk or a CD-ROM.
6. Insert the Windows XP installation disk into the disk drive. Close all windows and restart your computer.
7. Boot the computer from the Windows XP installation disk.
8. Press 'F2' at the text section of 'Setup' and insert your Automated System Recovery floppy disk or CD-ROM (only if you have two CD drives on your computer).
9. Follow the directions and see if this works to restore your computer. If it doesn't work, move on to Step 10.
10. Restart the computer again and press 'R' once setup starts to get into the Recovery Console.
11. Wait to be prompted to log in as an administrator. If you don't have an administrative password, press 'Enter' to bypass the prompt.
12. Type the following lines of information into the Recovery Console command screen and press 'Enter' after 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
13. Type 'Exit' and press 'Enter' to restart your computer. If you've previously done an NTBackup or a System State Backup, this should be the final step. If you haven't, continue to Step 14.
14. During the restart, press 'F8' to start the computer in Safe Mode.
15. Start Windows Explorer and click on 'Tools.'
16. Click on 'Folder Options.'
17. Click on 'View.'
18. Click on 'Show hidden files and folders' and uncheck the box next to 'Hide protected operating system files (Recommended).'
19. When you are prompted to show the files, click on 'Yes.'
20. Click on the drive that contains the Windows XP installation, and a list of folders will appear.
21. Open the 'System Volume Information' folder.
22. Open one of the previously created System Restore folders inside the System Volume Information folder by clicking on 'View' and 'Details' to see when a System Restore folder was created, and opening a folder that isn't current.
23. Open a Snapshot folder and copy these files to the 'C:\Windows\Tmp' folder:_REGISTRY_USER_.DEFAULT
_REGISTRY_MACHINE_SECURITY
_REGISTRY_MACHINE_SOFTWARE
_REGISTRY_MACHINE_SYSTEM
_REGISTRY_MACHINE_SAM
24. Rename the files in the Snapshot folder as: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 SAMThis will allow you to access these files and replace the old faulty System32 files when you run the Recovery Console in the next steps.
25. Close all windows and restart the computer.
Setting a Working Restore Point
26. After restarting your computer, press 'R' at the start of Setup to go into the Recovery Console.
27. Type the following lines of information at the command prompt and press 'Enter' after each line:del c:\windows\system32\config\samdel c:\windows\system32\config\securitydel c:\windows\system32\config\softwaredel c:\windows\system32\config\defaultdel c:\windows\system32\config\systemcopy c:\windows\tmp\software c:\windows\system32\config\softwarecopy c:\windows\tmp\system c:\windows\system32\config\systemcopy c:\windows\tmp\sam c:\windows\system32\config\samcopy c:\windows\tmp\security c:\windows\system32\config\securitycopy c:\windows\tmp\default c:\windows\system32\config\default
28. Type 'Exit' to restart your computer.
29. Log in and click on 'Start.' Run the mouse pointer over 'All Programs,' 'Accessories' and 'System Tools,' and click on 'System Restore.'
30. Restore the computer to a previous Restore Point; after your computer restarts and the changes take effect, your System32 problems will hopefully be fixed.