It's just that the new installer format is not working with our... dunno, virus protection thingamajig, so we are stuck at VS2015.
 I sort of  understand what is happening (real time checking), and when installing R packages changing some timeout helps.
 I'm a Linux user, or have been for the last 20 years. The last Windows stuff I did about 10 years ago on Win2k (also in my then job). Alas, the new place is a Microsoft shop... (but I do admit that VS is not that bad to use, with vi keybindings)