I am running a (Windows) computer with very limited personal hard disk space. The R library takes a lot of this space, that is why I was looking into its disk usage. I found three locations with a library inside:
C:\Program Files\R\R-3.5.2\library
Z:\R\R-3.5.1\library (Z:\ is my personal drive)
Z:\R\win-library\3.5
I am wondering why this is the case because I have merely installed R 3.5.2 and RStudio. .libPaths() returns
When you install a new version of R the default behavior is to keep the old version too, if you don't want to have it anymore, then you should uninstall it and manually delete the corresponding library folder.
Also, there are two default locations for your libraries, the one under program files holds libraries installed system wide, and the other one holds libraries installed just for your specific user.