If your PECD was built on a SP2 computer and then you either are trying to edit it on another SP2 PC or a re-imaged/Formatted one then it will not work, I don't know why but it won't, MS has no idea either(supposedly). Anyhow you can still use a XP SP1 and earlier to edit the registry, you can see what I mean when you load the hives and some of the larger key sets error out. So your options are #1 Rebuild - Always a good option #2 Use a Pre SP2 PC I have only tried XP and 2000. HTH EDIT BTW can you please attach the list of files in a txt file or something, if not remove it completely, annoying to scroll through.