R in QGIS not working after change of computers

I have installed, uninstalled a couple of times, but still get the same issue. Windows 7 and QGIS 3.6.1 and latest versions if R and R Studio. It used to work perfect until I changed computers.

R execution console output
Warning in install.packages("sf", dependencies = TRUE) :
'lib = "C:/Program Files/R/R-4.0.3/library"' is not writable
Error in install.packages("sf", dependencies = TRUE) :
unable to install packages
Calls: tryCatch ... tryCatchList -> tryCatchOne -> <Anonymous> -> install.packages
Execution halted