Microsoft KB Archive/889743

= Windows XP Service Pack 2 (Part 9): Uninstalling Service Pack 2 =

Article ID: 889743

Article Last Modified on 2/6/2007

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APPLIES TO

 Microsoft Windows XP Service Pack 2, when used with:  Microsoft Windows XP Home Edition

 Microsoft Windows XP Professional 

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Important This article contains information about how to modify the registry. Make sure to back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows registry



SUMMARY
This article is Part 9 of the Windows XP Service Pack 2 - Step by Step guide. This article describes how to uninstall Microsoft Windows XP Service Pack 2 (SP2).

To view the other articles in the Windows XP Service Pack 2 - Step by Step guide, see the Microsoft Knowledge Base articles that are listed in the &quot;References&quot; section.

The Windows XP Service Pack 2 - Step by Step guide includes the following topics: Part 1: Better security with Service Pack 2

Part 2: Installing Service Pack 2

Part 3: The new Security Center

Part 4: Automatic Updates

Part 5: Virus protection

Part 6: Windows Firewall

Part 7: Protecting against buffer overflows

Part 8: Improvements in Internet Explorer and Outlook Express

Part 9: Uninstalling Service Pack 2



Part 9: Uninstalling Service Pack 2
A Windows XP-based computer may not operate as expected after you install Windows XP SP2. You may be able to solve problems by using the firewall settings or the Data Execution Prevention (DEP) feature. However, some software programs that are installed on the computer may be incompatible with Windows XP SP2. The software manufacturer may not have released an update.

In this case, you can uninstall Windows XP SP2. To do this, you typically use the Add or Remove Programs item in Control Panel.

How to use Control Panel to uninstall Windows XP SP2
<ol> Click Start, point to Control Panel, and then click Add or Remove Programs.



</li> Click Change or Remove Programs, if it is not already selected.</li> Click Windows XP Service Pack 2, and then click Remove.



</li> Click Next.



</li> Click Finish to finish the removal of Windows XP SP2 and to restart the computer.</li> To make sure that the computer is adequately protected without Windows XP SP2, enable the firewall, update the virus protection program, and then run Windows Update.</li></ol>

How to uninstall Windows XP SP2 by using the Recovery Console
Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

If you can no longer start the computer after you install Windows XP SP2, you cannot uninstall Windows XP SP2 by using the usual method. In this case, use the Recovery Console to uninstall Windows XP SP2.

Before you can uninstall Windows XP SP2 by using the Recovery Console, the computer must be configured to start from the installation disk. Make sure that the installation disk is listed first in the basic input/output system (BIOS) boot sequence. There are usually instructions on how to do this in the user manual for the computer.

To uninstall Windows XP SP2 by using the Recovery Console, follow these steps: <ol> Insert the Windows XP installation disk into the disk drive, and then restart the computer.</li> Press any key to start the computer from the installation disk.</li> Press R when the Welcome screen appears.</li> Select a destination path for the Windows installation files, and then press ENTER.

Note The default location is C:\WINDOWS.</li> If a password has been set for the Administrator account, type the password, and then press ENTER. If no password has been set for the Administrator account, press ENTER.</li> At the command prompt, type the following commands, and press ENTER after each command:

cd $ntservicepackuninstall$\spuninst

batch spuninst.txt

exit

Note You may receive an &quot;Access Denied&quot; error message. This is not a problem. All important security data will be copied back.</li> Remove the installation disk from the disk drive, and then restart the computer.</li> Log on to the computer as you usually do.

Note Click No when you receive the Ignore the Windows Product Activation message.</li> Click Start, click Run, type regedit, and then click OK to open Registry Editor.



Note Alternatively, you can use the Task Manager Manager to start Registry Editor. To do this, follow these steps: <ol style="list-style-type: lower-alpha;"> Press CTRL+ALT+DELETE to start the Task Manager.</li> <li>On the Applications tab, click New Task.

</li> <li>Type regedit, and then click OK.

</li></ol> </li> <li>Locate and then click the following registry subkey:

</li> <li>Double-click the ObjectName entry, type LocalSystem in the Value data box, and then click OK.

</li> <li>Restart the computer.

Note If you cannot restart the computer as you typically do, press CTRL+ALT+DELETE, click ShutDown, select Restart, and then click OK.</li> <li>Open the C:\WINDOWS\system32 folder, and then locate the Wpa.bak file. This file is the backup copy of your Product Activation.</li> <li>Right-click the Wpa.bak file, and then click Copy.</li> <li>Right-click an empty area in the folder, and then click Paste.



</li> <li>Locate and then right-click the Wpa.dbl file, and then click Delete.



</li> <li>Right-click the copy of the Wpa.bak file, and then type wpa.dbl to rename it.



</li> <li>Restart the computer.

Note You will no longer be prompted to activate Windows XP.</li> <li>Remove the remaining Windows XP SP2 components. To do this, click Start, point to Control Panel, click Add or Remove Programs, select a component to remove, and then click Remove.

Note The Removal Wizard may display a warning before you remove a Windows XP SP2 component. You can safely ignore this warning. After you restart the computer, the component will function correctly.</li> <li>To make sure that the computer is adequately protected without Windows XP SP2, enable a firewall if you have one, update the virus protection program, and then run Windows Update.</li></ol>

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