CrystalBall© sez...

Updates are not installed successfully from Windows Update, from Microsoft
Update, or by using Automatic Updates after you repair a Windows XP
installation:
http://support.microsoft.com/kb/943144

NB: Also applies to clean installs, upgrade installs, and Recovery installs.

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Tip: Temporarily disable real-time protection by your anti-virus and/or
anti-spyware applications (e.g., CounterSpy, Spysweeper, Spybot Tea Timer,
AVG Anti-Spyware) and/or any third-party firewall (e.g., ZA) before
attempting to install the update(s). If you disable the third-party
firewall, make certain that you enable the Windows Firewall!

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How to troubleshoot Windows Update, Microsoft Update, and Windows Server
Update Services installation issues:
http://support.microsoft.com/kb/906602

1. See the "Need more help? Tell us what problem you are having" section of
http://support.microsoft.com/ph/6527

2. You cannot install some updates or programs
   http://support.microsoft.com/kb/822798

3a. Check Windowsupdate.log (%windir%\Windowsupdate.log) for errors
associated with the download/install.

How to read the Windowsupdate.log file
http://support.microsoft.com/kb/902093

3b. Compare errors to those listed here:
http://www.bleepingcomputer.com/blogs/mowgreen/index.php?showentry=1122
and/or go to http://windowsupdate.microsoft.com > click on Help and Support
link in left pane > Solve problems on your own.

4. Windows Update Checklist:
http://www3.telus.net/dandemar/updtcl.htm

5. Windows Update-specific newsgroup:
news://msnews.microsoft.com/microsoft.public.windowsupdate

Archive of Windows Update newsgroup:
http://groups-beta.google.com/group/microsoft.public.windowsupdate

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Start a free Windows Update support incident request:
https://support.microsoft.com/oas/default.aspx?gprid=6527

Support for Windows Update:
http://support.microsoft.com/gp/wusupport