My aplogies, I trolled for this and could not find... My technician machine: Windows Vista Business x32 SP1. Successful Catalogs: Vista Business x32(non SP1) Unsuccessful Catalogs: Vista Business x32SP1 I am able to select the non-SP1 .wim and create a catalog no problem. When I select the SP1 image, and try to catalog it, it hangs on 'Serializing Data'. It was left running overnight, and a CAT.EXE process ran for 18 hours. It never finished. My guess is that Windows SIM is notyetcompatible with SP1... Can anyone verify?