I have nLite 1.4.5 final. Slipstreaming XP Pro upgrade with SP3 in my Vista setup. I did a search but no results. I slipstreamed SP3 onto XP Pro that does not have any SP's slipstreamed into it. First I slipstreamed and make a bootable ISO. Then I tried an unattended slipstream. Both gave Product key not valid. It is a genuine key and the XP CD is the original that I paid for. Would either of these cause the error :- No previous SP's slipstreamed or Slipstreaming it in Vista ? Thanks for any help on this.