Hi there I am fairly new to this but I'm not sure where I'm going wrong: I'm trying to use the WIM Registry Editor to add in my own Reg tweaks into a windows 8.1 Pro x64 ISO and I get the following errors when trying to open the editor: I click OK past that error and get then get this: And once more after clicking OK past that I get this: And that last one I can't close, I have to kill the process in task manager. **NOTE** This also happens when I try to apply anything from within the All-In-One settings I get the same Unknown Mount error with the same details of 'A required privilege is not held by the client' - but I can click ok past it and it carries on applying settings (or that's what it looks like). However when I install the ISO on a virtual machine none of the changes are present. I'm running Windows 7 Pro x64 on the host machine, and I'm trying to create a Windows 8.1 Pro x64 (With all the updates streamlined, as well as a few silent installs for the likes of Flash player, Java etc. - Also got a few addons for VLC player and 7Zip, plus a single themepack. - And as I said before also trying to add in my own registry tweaks.) Thanks in advance. Jon.