I use a Mac myself, so I don't personally have this problem. However, I teach intro Stat and essentially all of my students with windows computer have the following experience.
On the first attempt at creating a markdown document, there is a popup that offers to install some mandatory packages.
This almost always fails. I've never had a report of success. This is true of both windows 8 and windows 10.
I've discovered the workaround, which is to enter the following command in the console.
This almost works perfectly, but there is usually a required package, recently formatR and/or rlang , that is not installed. This prompts a return to the popup dialogue, which does work in this case.
I'm not desperate about this since I have the workaround, but it does leave my students with diminished faith in R.