My parents can use Windows pretty well. Mum is 62, so used pcs at work until her retirement 2 yrs ago and Dad is nearly 70. With some of Mum's retirement cash, they decided to get a laptop. Good idea, thought I... until my little brother, who lives abroad, suggested that they get an Apple laptop as they are, according to him, 'much easier to use than Windows'. Well, yes, they are easier, when you are a bloke in his early 30s who's been using them for a decade, mainly for music-making. For some reason, and despite being told by me and every single shop assistant they spoke to that they should stick to Windows, my Dad was insistent that they got an Apple laptop (apparently so as not to offend my brother's suggestion, as he doesn't see them often and I live nearby and always help out).
That bloody thing has been the bane of my life for the last 2 yrs. Apart from it running ridiculously slowly because they let my brother fill it with all sorts of fancy programmes that they will never need and never use (and are scared to delete in case it breaks the laptop - sigh), my Dad rings me at least 3 times a week asking me to either instruct him how to do/solve something on the phone or to come over and help. When I point out that I have never used Macs and have no idea how to help, he gets really angry. Half the time, however, he rings me in a flap because a page has failed to load or a video has frozen; I cannot get him to understand that these things just happen sometimes and that I can't do anything special to help. It's got worse since I introduced him to YouTube.
He also has no idea how to 'read' an internet page - he often rings me in a panic claiming that there is no 'buy now' button on Amazon. AND he seems incapable of learning or understanding the simplest terms - when he rings in a flap, I can't even get him to understand how to 'scroll down' a page or minimise a page: 'Do you see the slider thing on the right hand side of the page?' 'No' 'Look at the very right hand side of the web page' 'Okay...' 'There's a sort of column with a button in it that you can move with the cursor' 'I'm telling you, there's not one! And what's a cursor?'. And so on, until Mum hears him on the phone, shouts at him for bothering me with nonsense, then shows him herself for the 100000000th time that week.
We once had a blazing row because he asked me how to do something and I just didn't understand what he was asking. I even rang DP to get him to speak to him in case I was being dense. After a good 30 mins, I finally realised he wanted to know how to send a photo in an email. At no stage of his explaining had he used the words 'photo', 'picture', 'email' or 'send'.
Do not get me started on how he only turns his mobile on if he needs to make a call because otherwise 'people will be able to ring me' 
I wouldn't mind, but he's a life-long member of Mensa and practically a mathematical genius. GAH! I love him dearly, of course.
Mum can use both the Mac and her mobile phone fine and is a more prolific texter and pic-taker than most teens 