When you visit Windows Update, it lists items that you have already installed?
This behavior will occur if the installed updates are not properly registered.
To fix the problem:
01. On the Windows Update site, select the mis-registered updates and press Install now.
02. Press Yes if prompted to install any required software or device drivers.
03. Shutdown and restarted your computer if prompted.
04. Repeat steps 1 and 2 to see if the new install corrected the problem. If the problem is resolved, exit this procedure.
05. Record the Microsoft Knowledge Base articles that have been mis-registered.
06. Use the Registry Editor to navigate to:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows XP\SP1.
07. Expand the SP1 key.
08. Select a Microsoft Knowledge Base article, Qnnnnnn, that is mis-registered and delete it's sub-key.
09. Press Yes to confirm the deletion.
10. Repeat steps 08 and 09 for each mis-registered update.
11. Exit the Registry Editor.
12. Shutdown and Restart your computer.
13. On the Windows Update site, select the mis-registered updates and press Install now.
14. Press Yes if prompted to install any required software or device drivers.
15. Shutdown and restarted your computer if prompted.
