Ran into the same issue using riprep and was able to resolve the issue by following the instructions on the Unattended install Tutorial or whatever its called, specifically the information on this page: http://unattended.msfn.org/unattended.xp/view/web/36/ The last step requiring you to compress the iastor.sys is very important. Regards, Tony Perf PS. Don't listen to that cluberti guy, he's evil and I hear that bread makes him pooh, yaaay!