Re: Upgrade? Why?
I think you over-worry. I have already made the experiment. Swapping Windows for Linux. For the users who never tinker with the system, all they care is where to click to use a few apps: browser, file navigator, sometimes the calculator. How to power off? No need, automatic sleep. Training time: 30 minutes max. These low tech users never complain.
For users who are more advanced. Who know windows registry edit, proficient with control panel, tweaking hardware, use utilities. These people are hard to convert. Even if they immediately understood how to use Linux after I setup the machine. They will reinstall Windows by themselves. Some even know how to Install pirate software and cracks they know where to find. For these cases, I gave up, not worth my time to explain further.
Then there is another case where people prefer to stick with Windows b/c they get used to a software. This could be a board game or an old local MS Office. This requires some works and learning to find a Linux substitute. Once done, they don't care if the machine is Linux or not.
Overall, for the non-tech users, if there is a geeky friend around to help for support, they have no problem to switch to Linux. Because the biggest hurdle is actually how to put Linux in their machine.
Without that help, they stick with Windows. Even though they know it could be unsafe. They just hope/think that in case of big security issue, this would happen to someone else.