Usually when someone older wants their PC fixed, I tell them, "It needs a full reinstallation," I backup their stuff, I install Linux Mint, and they're amazed by it when I give them the tour. When I tell them it's a Linux-based OS or it's not Windows, they are left speechless. Everyone I've installed Mint for, well over ten people now, has stuck with it even given the option to return to Windows. I think Mint's a great way to show people just how user-friendly Linux-based systems can be out-the-box (not to mention privacy and security, and the not having to subscribe to a thousand MS products to get a basic functional work PC -- what I end the tour with).
Even my mother of 65 is more at home on Debian+XFCE than she ever was Windows (since I setup her notebook when I bought it for her, I installed Debian to ensure less calls for help -- and there have been hardly any since I got it for her about 5 years back). She finds her best friend's Windows notebook, "terrible" and "a mess" -- that from a 65 year old!