Linux: ./keyhunter.py /dev/sdc
/dev/sdc is a "device" like a harddisk... unfortunately, you can't do this in Windows. It doesn't work that way.
It does work just fine on Windows. The syntax is something like
keyhunter.py \\.\PhysicalDisk2 . Of course one does have to use "elevated command prompt" a.k.a. "run as administrator".