Ah yes, I remember reading about downloading the tool to create the installation media now. Thanks. Maybe should make one just in case Windows ever decides to stop working.
Incidentally, according to this article from April, you can install from a downloaded copy of Windows 10 using a 7, 8 or 8.1 key and this will activate fine. You can even ignore the prompt for a key and it will still work, but nag you to activate every so often.
Difficult to say. My own desktop PC is an upgrade on top of 8.1 and I can't recall any particular issues with that. I've just installed 7 followed by 10 via the 'assistive technology' route onto my old laptop. I suppose if you have a much-used system which may have all kind of incompatible registry settings and programs set up for the earlier version you may have issues. But then again, most (all?) of the system files are stuffed into a Windows.old folder and replaced. That said, most of my installs have been clean.
never trust a man in a blue trench coat, never drive a car when you're dead