I installed this on my wife's PC 3 timnes over the week-end as part of a total rebuild (other problems I won't bore you with). SP1, then all the other updates all installed without a hitch. I can only think that you have something corrupt on your system which is stopping the update. As you will have no idea when this might haver happened, restore points are unlikely to resolve this issue, but you may find that the repair facility on your install CD will crack it for you. The other alternative - why not try to install directly reather than saving it first?