Installation Failure Error Code: 0x643 SP1 Failure

On Win XP Home Edition

I have done the following:
1. Uninstalled all .NET updates and the entire .NET Framework and
reinstalled the framework.
2. Uninstalled the Windows Updater 3.1 and reinstalled it.
3. Verified that my permsission are set to Full in the .NET configuration
tool accessed via the Control Panel.

Checked other threads for fix Installation of .NET Framework service packs
is not completed if you first install security update MS05-004 Recall that
tread.

No Avail.

Any other suggestions????

Thanks To All Who Reply....