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How to repair Windows Xp installation in
order to recover personal data
Windows Xp repair options Windows Vista repair options Windows 7 repair options
   Due to various reasons after a restart or when you want to start your system it doesn't start anymore.
The resolution is usually operating system reinstallation. A correct reinstall requires to format the system
partition, but this way all your personal data which were saved on this partition will be lost. We recommend
first to try out various troubleshooting steps to repair your operating system and depending on system's
condition  after  repair you can decide if the system can be used further or if the reinstall is absolutely
necessary.
Note: Before starting a system reinstall please backup all data saved on the C:\ partition.

   These issues can appear because of these causes:

 - Inappropriate computer shutdown
 - A power outage which can lead to inappropriate computer shutdown
 - Driver Install or Uninstall ( installation of incorrect drivers )
  - Programs Install or Uninstall ( installation of  programs  that aren't compatible with the system)
 - Virus infection (After a virus infection in most cases the system is heavy affected and system files are
    corrupt or even deleted. This causes the system to malfunction and even not start properly)

   In this kind of situation first step will be to Press the F8 key ( or F5 key) before your windows start in order
to have access to Windows Advanced Options Menu.

   First option that should be chosen from this Menu is Last Known Good configuration(your most recent
settings that worked).
   If this didn't fix the issue and the system it's in a continues restart loop and you aren't able to determine  
the error choose  Disable automatic restart on system failure. This will help you identify the error and then
the cause of the system failure.

   Second step is to boot in Safe Mode and from here you are able to uninstall any driver or installed  
software which caused the system failure. Within safe mode you have good chances to disinfect the system
of viruses .
Note:In order to be able to download and install security software to disinfect the system access Safe mode
with Networking.This way you will have internet access.

   If the system is still not able to start, nsert the Windows XP CD into your CD drive and restart your
computer. If you are prompted, select any options required to start (boot) from the CD. When the text-based
part of Setup begins, follow the prompts. Select the repair or recover option by pressing R. If you have a
dual-boot or multiboot system, select the installation that you want to access from the Recovery Console.
When you are prompted, type the Administrator password.

 - First steps is to repair boot , mbr  and disk errors using cmd .
 - Second step is to identify if your system cannot start because is missing files, dlls or your registry files
    are damage.

   If all above steps have failed to repair your system do a repair installation ( the system partition will not
be deleted ). We recommend this type of reinstall because you will be able to recover your data and once you
have recovered them you can prepare for a clean install.
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   What is Last Known Good Configuration (your most recent settings that worked)?

   It's a Windows startup option that uses the most recent system settings that worked correctly. Every time
you turn your computer off and Windows shuts down successfully, important system settings are saved in the
registry. You can use those settings to start your computer if a problem occurs. For example, if a new driver
for your video card is causing problems, or an incorrect registry setting is preventing Windows from starting
correctly, you can restart your computer using Last Known Good Configuration.
   What is Disable automatic restart on system failure ?

   Disable automatic restart on system failure prevents Windows from automatically restarting if an error
causes Windows to fail. Choose this option only if Windows is stuck in a loop where Windows fails, attempts
to restart, and fails again repeatedly.
   What is Safe mode?

   Safe mode is a troubleshooting option for Windows that starts your computer in a limited state. Only the
basic files and drivers necessary to run Windows are started. The words "Safe Mode" appear in the corners
of the display to identify which Windows mode you are using. If an existing problem does not reappear when
you start in safe mode, you can eliminate the default settings, programs and basic device drivers as possible
causes.
Note: Safe mode with networking starts Windows in safe mode and includes the network drivers and
services needed to access the Internet or other computers on your network.
   What is Recovery Console ?

   The Recovery Console gives you limited access to the NTFS file system, FAT, and FAT32 volumes. Recovery
Console prevents the familiar Windows Graphical User Interface (GUI) from loading in order to repair and
recover Windows functionality.
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   Fixboot

   Use this command to write the new Windows boot sector code on the system partition. In the command
syntax, drive name is the drive letter where the boot sector will be written ( because you are already in
system partition you can use just fixboot ). This command fixes damage in the Windows boot sector. This
command overrides the default setting, which writes to the system boot partition.
   Fixmbr

   Use this command to repair the MBR of the boot partition. In the command syntax, device name is an
optional device name that specifies the device that requires a new MBR. Use this command if a virus has
damaged the MBR and Windows cannot start.
   Chkdsk

   Chkdsk (Chkdsk.exe) is a command-line tool that checks volumes for problems. The tool then tries to repair
any that it finds. For example, Chkdsk can repair problems related to bad sectors, lost clusters, cross-linked
files, and directory errors.
Note: We recommend to use chkdsk  with the attributes /f /r and pay attentions to the letter of your
operating system in this case is C:

Use this command chkdsk /f /r c:
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   How to Troubleshoot a missing file in this case Ntldr

   When you start your system you will receive “NTLDR is missing”
Using recovery console you can copy the file that you need from your installation disk to the system partition.
In this case the drive letter for cd-rom is e: To be sure you can go on the drive and give the dir command to
view the files on the selected drive. Once you are sure of the drive letter you can copy the ntldr file from i386
directory to your system partition drive, in this case c:, then you can exit.

copy e:\i386\ntldr c:\
   How to Troubleshoot a missing dll in this case hal.dll

   When you start your system you will receive “Windows could not start because the following file is missing
or corrupt: <Windows root>\system32\hal.dll. Please re-install a copy of the above file”
Using recovery console you can copy the file that you need from your installation disk to the system partition.
In this case the drive letter for cd-rom is e: To be sure you can go on the drive and give the dir command to
view the files on the selected drive. Once you are sure of the drive letter you can expand the hal.dl_ from
i386 directory to your system partition drive, in this case c:, to the correct path then you can exit.

expand e:\i386\hal.dl_ c:\windows\system32
   How to recover from a corrupted registry that prevents Windows XP from starting

   When you try to start or restart your Windows XP-based computer, you may receive one of the following
error messages:

 - 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
 - System error: Lsass.exe
   When trying to update a password the return status indicates that the value provided as the current
    password is not correct.

To resolve this you need to follow this procedure:
Assuming that the drive letter for your system partition is c: write the following commands in
recovery console:

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

Once you have access to your operating system use system restore to revert your windows to a point when
is working fine:
Start->All Programs->Accessories->System Tools->System Restore-> click Restore to a previous RestorePoint..
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