Downloaded the Nano AMD64 img file and tried to use physdiskwrite -u to write it to my usb
Failed to open \\. \PhysicalDrive1 - exiting
BINGO, used rufus with vga amd64 img and worked like a charm!!
Weird, but good to know. :)
BTW, the Nano image is not a installation image. It is a preinstalled system for SD/CF cards or USB sticks...