I've seen some ISOs floating around which say they'll correctly install Windows 7 and Vista packed as ESDs, despite that being a format which only works with Windows 8's version of DISM, AFAIK. When I booted off of one of these, they showed what appeared to be Windows 7 Setup, but within Windows 8 PE/RE, as evidenced by going to the "Repair" option. Looking within the PE, there seems to be some files which are Windows 7 version that should be Windows 8 version, such as the "spwizimg.dll" file. Using an ESD over a WIM saves a considerable amount of space on a 32GB and smaller Flash Drive --- I can fit Vista,7, & 8 in 12GB --- and I find sometimes the great WinNTSetup tool doesn't always work with an image, where the original Windows Vista or 7 Setup always seems to work. Any clues on how this was done, and could I use something like it (with multiple setup PEs) to just install from one single ESD with 8, 7, and Vista?