I finally deleted all of the folders by drilling down to the almost endless copies of Application Data and moving subsequent levels to the root of the D: and deleting piece by piece. I have no idea how those copies were made in the first place, and secondly, why Windows makes it so hard to delete such a nasty, unwieldy folder structure. Ugh!
next time it happens
At a command prompt with elevated level (Start -> type cmd -> rightclick cmd > run as administrator)
try the following:
cacls D:Foldername /T /G Everyone:F
rmdir /s /q D:Foldername
This command should delete any folder whatsoever