Repair XP

Following are my experiences with repairing XP. I will not assume any responsibility for problems that may occur to your system from using any of these suggestions. It is always prudent to backup important data before you make any changes to your operating system.

Windows Update Site Problems - Jupiter Jones MS MVP
Repair System Restore - Bert Kinney MS MVP
How To Uninstall SP2 Using the Recovery Console - S Raj Kumar Rathi (scroll to August 17, 2004)
How To Use The Automatic Recovery Feature to Recover From a Bad SP2 Install - Microsoft
How To Remove SP2 using a Repair Install
How To Access Safe Mode
How To Access Last Known Good Config
How To Backup, Edit and Restore the Registry - Microsoft
How To Create a Boot Disk to Start Windows XP
How To Create a Slipstreamed version of XP
How To Fix :NTLDR is missing press any key to restart - From Miles Cromer
How To Fix and "Invalid Boot.ini" or "Windows could not start........Hall.dll "error - Microsoft Knowledgebase
Cannot Start Windows XP if the System or Software Hive Is Missing or Damaged  - From Kelly Theriot
Password Problems and Windows XP - From Kelly Theriot
How To Fix The Cryptographic Service Error - Fix for  "Error:Setup could not verify the integrity of the file Update.inf. Make sure the Cryptographic service is running on this computer"
System Cannot Access CD-Rom, CD-Recorder or DVD Devices
Error Messages After Removing Easy CD Creator from XP
Introduction to using System File Checker - SFC /SCANNOW
SFC (System File Checker) has a problem running -  SFC /SCANNOW keeps asking for the XP CD
How to log on to Windows XP if you forget your password
How To Take Ownership of a File or Folder
How To Access Recovery Console
Recovery Console in Windows XP - From Kelly Theriot. This is a must read
How To Backup, Edit and Restore the Registry in XP - Microsoft Knowledgebase Article.
How To Create a Set of Emergency Floppies - If your computer can not boot from a CD-Rom create a 6 floppy disk set that corresponds to your version of Windows XP. Click here for Home Edition  Click here for  Pro Edition
How To Create a bootable CD to access the Recovery Console - this 7Mb .iso will give you a bootable Recovery Console rather than using the  6 floppy set above. Unzip and burn the .ISO file to disc. You can boot the CD and run the Recovery Console (use this link if the first doesn't work )
How To Repair Boot sector
How To Format
How To Partition
How To Exit the Recovery Console
How To Run a Repair Install
How To Uncover Windows XP Product Key
How To Change The Product ID
A better boot diskette for WinNT/2000/XP
Has XP Been Activated?
NTFS Reader for DOS (freeware) - lets you access an NTFS partition from a floppy and copy files off it
Known Issues with Windows XP Service Pack 1
AIDA32 - AIDA32 is a professional system information, diagnostics and benchmarking program running on Win32 platforms. It extracts details of all components of the PC. You can even uncover your Windows XP and Office 2000/XP Product Keys with this freeware app. READ the FAQ!!!
Tweaks&Fixes - From Kelly's Korner this is a fantastic set of registry hacks and fixes.
NTBackup Is Missing From My OEM version of XP (download)- Some OEMs don't include NTBackup - Bob Cerelli has it at his site in his Windows XP Tips section
Knoppix - Ok this might appear to be blasphemy on a site dedicated to Windows but if your system is really hosed and you are desperate to get data off the drive then give Knoppix a go. The download is a whopping 700MB but you get an ISO that, when burned to CD, creates a version of Linux that runs directly off the CD and doesn't require installation to your Hard Drive. With this CD Operating System you can access your NTFS or FAT partitions and with it's built in CD Burning software copy your important data off the drive . Or if you have a network you can transfer files to another system. This is a must have!

How to access Safe Mode:
Reboot your computer while holding down the F8 Key. At the Advanced Options Menu select the option for Safe Mode and press Enter.

How to access Last Known Good Configuration:
Reboot your computer while holding down the F8 Key. At the Advanced Options Menu select Last Known Good Configuration.

How to access the Recovery Console: - take this link for more information
The Recovery Console is a set of tools which run from a Command prompt. If your system is formatted as NTFS then these tools can help you manage the  partition. You can learn more about the Recovery Console through Help and Support  or
Click here for information about the different commands and their functions .

To run the Recovery Console  from CD boot with the Windows XP CD (or with the optional 6 floppy disk set) and select "R" at the Welcome Screen.

The screen will switch to black and you will be asked which installation to log on to. If you only have one installation you will press "1". Remember that numlock is off at this time.

Next you'll be prompted to enter your Admin password. By default it is created blank so just press Enter.

At the C:\Windows command prompt type "Help" for a list of commands you can use.

How to Repair the Boot Sector:
If XP won't start it may be due to a damaged boot sector or a missing or corrupt ntldr  or ntdetect.com files. 

To replace damaged ntldr and ntdetect.com you can copy fresh files from the XP CD using  the COPY command. Boot with the XP CD and enter the Recovery Console (as above). At the Command Prompt type the following (where "X" is your CD-Rom drive letter) allowing the files  to overwrite the old  files
        COPY X:\i386\NTLDR C:
        COPY X:\i386\NTDETECT.COM C:

To repair a damaged Boot Sector at the command prompt type FIXBOOT and press Enter. Then answer "Y" 

How To Format using the Recovery Console (click for info on How To Access The Recovery Console)

How Partition using the Recovery Console: (click for info on How To Access The Recovery Console)
At the command prompt type DISKPART and press Enter.

An interface is displayed which you can move through with the Arrow Keys. Press "C" to create a partition in unused space. Pressing "D" will delete the highlighted partition.

How To Exit the Recovery Console:
You can not use Ctrl+Alt+Del to quit the Recovery Console. Instead type "EXIT" at the command prompt and Windows will be started.

Boot to Windows.

How to Repair Install:  ***Also removes Service Packs***
Sometimes the only way to repair XP is to reinstall. You do not have to wipe your partition and start over. Just as with previous versions of Windows you can reinstall right over top of an existing setup. This has the advantage of retaining your installed applications, data and settings. You will lose previously saved System Restore Points but System Restore will begin creating new restore points again immediately following the Repair Install. You will need to reinstall SP2 and any Critical Updates from the Windows Update Site. Be aware that a Repair Install will leave your system vulnerable to the Blaster and Welchia worms. Do not go on line until you have enabled XP's firewall first. Then visit the Windows Update Site to patch your system  It is always prudent to backup important data before you make changes to XP.

There are two approaches. The first one should be used if you can still boot to your Windows Desktop. Simply pop the XP CD into the CD-Rom drive and select Install->Upgrade[recommended]. This will install XP overtop of itself in the same way as upgrading from a previous setup. However if your version is an OEM version then you will not have this option. If you do not see the option to Upgrade[recommended] DO NOT choose New Install as that will either overwrite your current setup completely or give you a dual boot setup. Also if you have an older version of XP and have upgraded to a new service pack you will get a message stating that a newer version of Windows was found and you will not be able to run the Upgrade. Create a Slipstream version to solve this problem

If you cannot boot to the Desktop, or you have an OEM version of XP, or you want to remove a service pack then the following should be used to complete a Repair Install.

Boot with the Windows XP CD and at the Setup Screen press the Enter Key

You will be taken to the Windows XP Licensing Agreement. After reading the agreement press F8 to proceed.

The next screen gives you the option to do a fresh (clean) install or to repair the selected Windows XP installation. To run a Repair Install Press "R" at this time.
***CAUTION*** if you do not see the option to repair the selected Windows XP installation DO NOT choose the option to continue installing a fresh copy without repairing as that will overwrite your data and cause unrecoverable data loss.

Windows XP will copy the necessary files to your Hard Drive to begin the installation  and will then reboot. You will see the message that informs you to "Press any key to boot the CD". Do not press any keys this time just wait a few seconds and the Windows Startup Screen will be displayed. Following this you will be greeted by the Windows XP Setup Screens.

When Setup has completed you should find all of your previously installed apps and settings are intact.

How To Determine If XP was Activated?
You installed XP and then can't remember if you activated it. Go to Start->Run and enter the following
 oobe/msoobe /a

View Product Key XP - Visit the Keyfinder Homepage   by Aleks Ozolins
If you have more than one system running XP you have obviously purchased more than one copy of the Operating System. However you may have forgotten which Product Key you used for which system. It happens. I have 5 systems and have had all of them running XP at times.  XP does not store the Product Key in a recognizable format in the registry. 
Click this link and select "Open" and your Windows XP Product Key will be displayed 
Keyfinder is a freeware utility that retrieves your Product Key.  has the options to copy the key to clipboard, save it to a text file, or print it for safekeeping. It works on Windows 95, 98, ME, NT4, 2000, XP, Vista, .NET, Office 97, Office XP, Office 2003 and Office 2007. It even has the ability by using Microsoft's own script to change installation keys. See the Microsoft Knowledgebase article here Q328874
If your version of XP came pre-installed on your computer the revealed Product Key could be that of an image used by the manufacturer. If this is the case you will likely be unable to use it to install another version of Windows XP such as one purchased separately from the computer. Find an alternate location for ViewKeyXP if my link is broken.

Known Issues with Windows XP Service Pack 1
Fix Switch Identities in Microsoft Outlook Express After Service Pack 1
HP/Compaq SP1 Notice - The System Restore feature in these computers seriously conflicts with SP1
Cannot Start Windows XP After Installing Service Pack 1 and Then Performing a System Recovery Operation
Fix for SP1 Problems and Compaq Pressario 6330
Microsoft Knowledgebase Articles Pertaining to Windows XP SP1
Setup Could Not Verify the Integrity of the File" Error Message Occurs When You Try to Install SP1
'The Password Is Not Valid' Error Message Appears When You Log On to Recovery Console in Windows XP