Changing the default library folder path in R
A simple procedure in Microsoft Windows for setting the default library folder for installations of R.
Installations of R will tend to install libraries at C:/Program Files/R/R-X.X.X/library, which may not always be writable. The only way to effectively change this default resides outside of R in Microsoft Windows.
In the Microsoft Control Panel, go to System and Security > System > Advanced system settings > Environment variables.
A new environment variable should be created by clicking on “New…” and entering R_LIBS_USER as the variable name and C:\Path\To\R-Libraries as the variable path (change as appropriate).
Save the changes and restart R. Packages should now be saved to the new location.
The PowerShell Method
Another method for achieving this in the command line is via Windows PowerShell:
[Environment]::SetEnvironmentVariable("R_LIBS_USER", "C:\Path\To\R-Libraries", "User")