Umm.... quite probably you can copy perfect Amiga floppies on a windows machine. I haven't tried it but:
I use a program called Rawrite
It is available for MAc, Linux, Unix, and windows
It takes floppy 'images' and writes them straight to disk. This is usually most useful in wirting boot disks, or OS install disks. It is possible, but actually not so likely, that rawrite wouldn't be able to handle adf files, if they are simply perfect copies of the disk image though it should have no problems (it'll take any format, it justs directly writes the data)
Its rather irritating for someone like me that I have to use 3rd party products to handle image files.