Windows updates not getting installed in XP

ISSUE:

Updates are not installed successfully from Windows Update, from Microsoft Update, or by using Automatic Updates after you repair a Windows XP installation.

CAUSE:

This problem occurs because of how the Windows XP repair operation replaces Windows system files. When you repair a Windows installation by using a Windows XP CD, the repair operation performs both of the following operations:

•	It replaces all the Windows system files with the corresponding files from the CD. Note This includes the Windows Update files.
•	It restores the Windows registry.

The latest version of Windows Update includes a file that was not available in the release version of Windows XP. This file is named Wups2.dll. Therefore, after the repair operation is complete, the following situation exists:

•	The Wups2.dll file remains on the computer.
•	The registry entries that correspond to this file are missing.

Because the registry files that correspond to the Wups2.dll file are missing, update installations are unsuccessful.

RESOLUTION

Method 1: Register the Wups2.dll file in Windows

To register the Wups2.dll file in Windows, follow these steps:

1.	Stop the Automatic Updates service. To do this, follow these steps: a. Click Start, click Run, type cmd, and then click OK. b. At the command prompt, type the following command, and then press ENTER: net stop wuauserv
2.	Register the Wups2.dll file. To do this, follow these steps: a. At the command prompt, type the following command, and then press ENTER: regsvr32 %windir%\system32\wups2.dll Note For a computer that is running Windows XP Professional x64 Edition, type the following command, and then press ENTER: regsvr32 %windir%\syswow64\wups2.dll b. Click OK on each verification message that you receive.
3.	Start the Automatic Updates service. To do this, type the following command at the command prompt, and then press ENTER: net start wuauserv
4.	Exit the command prompt. To do this type exit, and then press ENTER.

Method 2: Download and install the Windows Update Agent

To resolve this problem, follow these steps:

1.	Download the appropriate version of the Windows Update Agent to a known location. To do this, visit one of the following Web sites. AgentWindows, x86-based systems http://download.windowsupdate.com/WindowsUpdate/redist/standalone/7.0.6000.381/WindowsUpdateAgent30-x86.exe (http://download.windowsupdate.com/windowsupdate/redist/standalone/7.0.6000.381/windowsupdateagent30-x86.exe) Windows, x64-based systems http://download.windowsupdate.com/WindowsUpdate/redist/standalone/7.0.6000.381/WindowsUpdateAgent30-x64.exe (http://download.windowsupdate.com/windowsupdate/redist/standalone/7.0.6000.381/windowsupdateagent30-x64.exe) Windows, Itanium-based systems http://download.windowsupdate.com/WindowsUpdate/redist/standalone/7.0.6000.381/WindowsUpdateAgent30-ia64.exe (http://download.windowsupdate.com/windowsupdate/redist/standalone/7.0.6000.381/windowsupdateagent30-ia64.exe)
2.	Click Start, click Run, click Browse, locate the file that you saved in step 1, and then click Open.
3.	Add the /wuforce switch to the end of the run command, and then click OK. For example, the run command may appear as the following: C:\WindowsUpdateAgent30-x86.exe"/wuforce
4.	Click Run.
5.	Follow the steps to complete the wizard.

Also, check the following link for other issues with the windows updates in XP:

http://v4.windowsupdate.microsoft.com/troubleshoot/#Other