Why can't I update XP anymore?

I can no longer update XP. Any idea what might be wrong?

When I go to Windows Update (http://www.update.microsoft.com/
windowsupdate/v6/default.aspx?ln=en-us), click on Express, it tries to
validate my Windows system. That fails. Why!?

It gives me the option to try an "alternate validation". That
works(!). But when it throws me back to the window and I click on
Express again, it again tries to validate my Windows system the
original way, which fails again.

Things I have tried.... Disabled Norton Internet Security. Reset IE6
Security and Advanced options to their defaults (medium level
security). In IE6, cleared history and deleted cookies and files
(including offline content). Added www.update.microsoft.com,
update.microsoft.com and windowsupdate.microsoft.com to Trusted Sites
(all http://...). Restarted the system after all of those changes.
Accessed Windows Update via Start >> Programs to ensure that there is
only the one IE6 instance running.

.

Relevant Pages

  • Re: Microsoft File?
    ... It is a valid Microsoft file, and was placed there the last time you visited ... windows update. ... you will be required to validate your copy of Windows ...
    (microsoft.public.windowsxp.basics)
  • Re: Validate
    ... You receive an error code and the copy of Microsoft Windows is not validated when you try ... to use Windows Genuine Advantage to validate your copy of Windows ... For assistance from Microsoft: ... Problems When Viewing or Downloading From Windows Update ...
    (microsoft.public.windowsxp.help_and_support)
  • Re: SOLUTION to Failed Updates XP Pro
    ... Windows update failure to install wrote: ... Depends on your Windows system & whether it is on V4 or V5 of Windows Updates. ... Your Windows is either at C:\Windows or C:\WINNT (like Pete). ...
    (microsoft.public.windowsupdate)
  • Re: Windows Update URL no longer functions
    ... Please fill out the form and let MS know what happened to your system so that they are aware of the damage done by Guided Help. ... The system basically comes up except that Windows Explorer took 15 minutes to finish what it was doing. ... That interference may be why the system will only access a blank page when invoking the Windows Update shortcut from the Start menu. ... All I can suggest you try at this point, besides uninstalling WinPatrol/Spybot and then rebuilding the winsock stack, is to Clean boot the system and then reset Windows Update's components via a Microsoft Fixit: ...
    (microsoft.public.windowsupdate)
  • Re: I cant install critical updates
    ... I resolved error message problem from Vista Security Center by uninstalling and reinstalling Antivir. ... How it comes I can't either manage to install manually failing updates? ... Be sure to obtain the correct version for Windows x86. ... Windows Update Agent File Versions: ...
    (microsoft.public.windowsupdate)