As mentioned by David Smith, R 3.4.3 is primarily a bug-fix release:
It fixes an issue with incorrect time zones on MacOS High Sierra, and some issues with handling Unicode characters. (Incidentally, representing international and special characters is something that R takes great care in handling properly. It’s not an easy task: a 2003 essay by Joel Spolsky describes the minefield that is character representation, and not much has changed since then.)
The full list of bug fixes and new features is provided below.
Upgrading to R 3.4.3 on Windows
If you are using Windows you can easily upgrade to the latest version of R using the installr package. Simply run the following code in Rgui:
install.packages("installr") # install setInternet2(TRUE) # only for R versions older than 3.3.0 installr::updateR() # updating R. # If you wish it to go faster, run: installr::updateR(T)
Running “updateR()” will detect if there is a new R version available, and if so it will download+install it (etc.). There is also a step by step tutorial (with screenshots) on how to upgrade R on Windows, using the installr package. If you only see the option to upgrade to an older version of R, then change your mirror or try again in a few hours (it usually take around 24 hours for all CRAN mirrors to get the latest version of R).