Whatever was happening suddenly stopped. Right click was causing random problems without further command - e.g., compressing!!!! All this suddenly stopped, perhaps after a reboot, but anyway I can 'Send' a folder or a file to a drive on the offered list of SendTo items. Dragging it to the list did the job just as it should.
Thanks folks for telling me how to find that list.
Okay, that works, but any attempt to send it to that (removable) drive -
and into a folder on that drive - fails. A second attempt tells me it's already there, but WTF it is nothing will reveal. Anyway, it has not arrived at the target. Yes, I've spent ages doing searches for that folder. The original is there, but no copies are to be found. Nothing in properties allows any editing to, say, put the drive letter before the target folder. Writing a simple address line like almost every program in the world uses, just seems forbidden.
I created that target just as I did the other - dragging the image of the folder into the send to list. Indeed, it shows on that list as a File Folder. Everything in Properties just shows the full address of the SendTo list.
Nothing I can do finds the sent folder. If it wasn't for the thousands of photos I need to sort I'd give up, but it's sooooooo handy to pick one and send it to one of a few targets all with one hand. Perhaps this handy tool is not so handy, and that's why so few people seem to use it.