This fixed the problem for me:
http://support.microsoft.com/kb/943144
Good luck...
"James" wrote:
> Hi,
>
> I recently updated to SP3 and I'm now finding that I cannot install updates
> from the Windows update site. I use AVG as my anti-virus and Sygate Personal
> Firewall. The following updates fail to install:
>
> Security Update for Windows XP with Windows Media Format Runtime 9.5 and 11
> (KB941569)
> Security Update for Microsoft .NET Framework, Version 2.0 (KB928365)
> Microsoft .NET Framework 1.1 Service Pack 1
> Security Update for Flash Player (KB923789)
> Windows Malicious Software Removal Tool - May 2008 (KB890830)
>
> PC Specs:
>
> AMD Athlon 3500 X64
> 1024 DDR
> Gigabyte GA-K8nXP-SLI
> Microsoft Windows XP SP3
>
> Has anyone else had this annoying problem??
>
> Cheers
>
> James