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10 things you should know about Windows XP's System Restore tool

How to restore Windows XP registry from a restore point using the recovery console

Your current registry may be missing or corrupted if you have an error similar to the one below. It may be due to an unscheduled shutdown/reboot and/or damaged hard-drive. Errors may look like:
Windows XP could not start because the following file is missing or corrupt: \WINDOWS\SYSTEM32\CONFIG\SYSTEM
Windows XP could not start because the following file is missing or corrupt: \WINDOWS\SYSTEM32\CONFIG\SOFTWARE
Stop: c0000218 {Registry File Failure} The registry cannot load the hive (file): \SystemRoot\System32\Config\SOFTWARE (or its log or alternate)

Windows could not start because the following file is missing or corrupt: c:\Windows\system32\config\system

To resolve this issue you may restore your registry from a restore point but have to use the Windows XP CD that came with your computer.

1. Boot off of a Windows XP CD. Press R to get to the recovery console.
Welcome to Setup: To repair a Windwos XP installing using Recovery Consule, press R.

2. Press 1 to log onto Windows. You will need the administrative password to get into to command prompt. If the administrator password was blank press enter. If your SAM and/or SECURITY registry is bad it will not prompt you for a password.
Which Windows installation would you like to log onto (To cancel, press ENTER)?

2. Change directory to the configuration folder to the c:\windows\system32\config folder. type: cd system32\config

3. Backup the current configuratioin by renaming 5 files. Type in the following commands (no particular order):

type: rename default default.bak
type: rename sam sam.bak
type: rename system system.bak
type: rename software software.bak
type: rename security security.bak

This will backup the current registry settings.

4. Switch to the system volume information folder. type: cd\

then type: cd "system volume information"
If you do not have access to the system volume information folder you will have to copy the registry files from c:\windows\repair folder and set permissions and passwords. Follow these instructions if you do not have access to the system volume information folder. You may continue with those instructions from step 4.

5. To see the directory type: dir

6. Change the directory into the restore folder that will have a similiarly long name but will look different on each machine. type: cd _restore{987E0331-0f01-427......}

7. to see the directory type: dir

8. Change into the rp directory with the lastest date. EX: If rp139 has the latest date type: cd rp139

9. Change the directory into snapshot folder. type: cd snapshot

10. To see the directory type: dir

11. copy and rename the files by typing in the following commands (no particular order):

type: copy _REGISTRY_USER_.DEFAULT c:\windows\system32\config\default
type: copy _REGISTRY_MACHINE_SAM c:\windows\system32\config\sam
type: copy _REGISTRY_MACHINE_SECURITY c:\windows\system32\config\security
type: copy _REGISTRY_MACHINE_SOFTWARE c:\windows\system32\config\software
type: copy _REGISTRY_MACHINE_SYSTEM c:\windows\system32\config\system

12. Type: Exit
The computer will restart. Take the Windows CD out of the drive.

You have just copied registry settings for that restore point from that date to the configuration folder. The next time you restart you will be restarting with those settings in safe and normal modes. If that didn't work try restoring to an earlier restore point. All of the passwords will be reset to whatever they were on that restore point date.

It is recommended to back up all the files and programs you need then reformat and reinstall Windows. Running a disk check is also recommended.

How to recover from a corrupted registry that prevents Windows XP from starting:
http://support.microsoft.com/?kbid=307545