Hi all. No BartPE does not use FreeDOS, as I understand it is a legal use of the Windows pre-install environment that loads prior to performing a full Windows install on a machine. I was not able to set the temp directory on-the-fly. However, it can be done. This is not really relevant to this forum but in case anyone does end up here trying to find a solution to a problem like mine. When using PEbuilder you need to edit the ramdisk plugin to set a temp directory that ExifTool can use. Find these 2 lines:
0x2, "ControlSet001\Control\Session Manager\Environment", "temp", "%RamDiskDriveLetter%"
0x2, "ControlSet001\Control\Session Manager\Environment", "tmp", "%RamDiskDriveLetter%"
and edit them to something similar to:
0x1, "ControlSet001\Control\Session Manager\Environment", "temp", "TEMP"
0x1, "ControlSet001\Control\Session Manager\Environment", "tmp", "TEMP"
This is manipulating BartPE's registry construction in such a way that the Temp directory is set to a location named "TEMP" which hangs off the System32 folder of a Windows installation.
Cheers!