if(!require(installr)) { install.packages("installr"); require(installr)} #load / install+load installr # using the package: updateR() # this will start the updating process of your R installation. It will check for newer versions, and if one is available, will guide you through the decisions you'd need to make.
Links:
http://www.r-statistics.com/2013/03/updating-r-from-r-on-windows-using-the-installr-package/
http://www.r-project.org/