From a console window. No problem in TC, where I can highlight text with a left-mouse-drag and then ctrl-c works OK.
Shift-left and shift-right do not show any highlight (for me) in a console window. However I tried shift-left on the command line and though I saw only cursor movement, contr0l-C did then copy the text I had cursored over. I have a COLOR 70 command in TCSTART to get a black-on-grey window, but I do not know if this is related to the lack of highlighting. Of course these keystrokes are of little use to me anyway because invariably (and I do this frequently) the destination is the command line and the needed text is elsewhere in the console window.
My goal is to be able to select text with a mouse anywhere in the console window and then (at last!) not have to remember to press Enter to put it on the clipboard, avoiding the swearing when I hit ctrl-C out of habit and have to start over again. It really looked as if TC 17 would solve this, but I may have to wait for CMD in Windows 10 instead.