Paste this into the console and run the commands:
## How to update R in RStudio using installr package (for Windows)
## paste this into the console and run the commands
## "The updateR() command performs the following: finding the latest R version, downloading it, running the installer, deleting the installation file, copy and updating old packages to the new R installation."
## more info here: https://cran.r-project.org/web/packages/installr/index.html
install.packages("installr")
library(installr)
updateR()
## Watch for small pop up windows. There will be many questions and they don't always pop to the front.
## Note: It warns that it might work better in Rgui but I did it in Rstudio and it worked just fine.