Edit: I know I can use aliases and .bat files and whatever to make one look like the other, sort of, but then I learn some patchwork system and will be unable to use any other computer's login.
Although I can't get copy/paste to work in a remote text putty window. Sigh.
I do know. But it isn't complete, whether it works or not depends on which command or program you're using. It's not really predictable.
Posix programs ported to Windows have similar problems - they often remain case sensitive with filenames.
At least all the programs I write work accept both \ and /, and are case sensitive on Posix and case insensitive on Windows.
Depends on stuff like what terminal Putty emulates and so on, of course, but... Eh, have you tried using the old "MS/IBM CUA standard shortcut keys, [Ctrl]-[Ins] and [Shift]-[Ins]? (And, for completeness' sake, [Shift]-[Del] for Cut.)
AIUI, those are Putty's standard keys for that. I've always assumed that's because, you know, a 'Nix command line would interpret [Ctrl]-[C] rather differently.