I am trying to install Untangle Server using downloaded versions of 7.01 and 7.2 burnt to CD. It reads the cd-rom (I have tried two others including a dvd-rom) and gets stuck on the step where it is supposed to pick up the preconfiguration file and displays message "Failed to process the preconfiguration file. The installer failed to process the preconfiguration file from file: ///cdrom/simple-cdd/expert-preseed. The file may be corrupt. I have extracted the files (7-Zip) and can see 6 files but don't know how to read or verify them for corruption. Any help would be appreciated.