People unfortunate enough to be on Windows 10 will have recently had (or soon will have) their machine out of action for upwards of half an hour, without any advanced warning of how long it'll take.
You think that's perfectly reasonable?
Well it is an option I didn't expect to have (thought everything would be 8 or newer), but... why?
I don't want "ok, well I can't do that over the phone, so remind me to have a look at it when I'm next down".
I want "ok, well since I have the exact same hardware and OS I'll figure it out here then let you know what to do".