WINDOWS XP UPDATES-Installing Same updates over again.

> I have downloaded and installed Windows XP Service Pack 1
> from the update website, plus other updates for Windows XP
> Pro. Even though the history says the updates have been
> installed successfully, when I revisit the update site I
> get the same updates appearing again down load install
> again reboot go back to the update the same files need to
> be downloaded again...When I check the Windows Version it
> says Windows XP Service Pack 1. The next day I checked
> again after setting up the Auto update, check the version
> again and the service pack 1 is gone. Go back to do the
> updates again..same thing happens. Just going around in
> circles