Hi I had a very similar experience with one of my machines some time ago. The build from cd was fine, no errors, but riprep image would give errors all over the place. Mine turned out to be a memory issue. One of the DIMMs was faulty. Replaced it and all was well. My other question would be, which service pack level is your flat cd install? Do you install a service pack as one of the updates? If so you need to slipstream the service pack into your flat cd install and re-create the reference machine, then riprep again. RIS doesn't like different service pack levels on standard and riprep sources. Taz