This is a great fix if you have a problem with the installation path; if the installation directory is different to the directory where the packages are stored.
References:
Changing R default library path using .libPaths in Rprofile.site fails to work
http://stackoverflow.com/questions/15...
Select Package Repositories
http://stat.ethz.ch/R-manual/R-patche...
Unable to update R packages in default library on Windows 7
http://stackoverflow.com/questions/50...
unable to move temporary installation
http://r.789695.n4.nabble.com/unable-...
Installing Packages in R Studio
• Installing Packages in R Studio
Package Installed: Genalg
http://cran.r-project.org/web/package...