Photoshop CS6 complete install in windows 10 - how? windows 10 doesn't.

Question should have said uninstall! Autocorrect is more dangerous than it is useful, sometimes.

That aside. I've uninstalled, rebooted, reinstalled, uninstalled, rebooted, run the cleaner tool (no errors) rebooted, reinstalled, repeat the latter but then do some manual cleaning up, too. It reinstalls cleanly, now, but I'm getting the message "file must be saved as a copy with this selection", still (which is why I wanted the comprehensive uninstall). I've clearly cracked the uninstalling. But not solved the problem. :-( (is there a very sad emoticon?)

The uninstall and cleaner had left some settings in place which were cleared when I reset these whilst starting photoshop. I am puzzled as to why all my uninstalling didn't clear this. But it works, now.