R.home()
# [1] "C:/PROGRA~1/R/R-31~1.1"
R.home("bin")
# [1] "C:/PROGRA~1/R/R-31~1.1/bin/i386"
R.home("doc")
# [1] "C:/PROGRA~1/R/R-31~1.1/doc"
R.home("etc")
# [1] "C:/PROGRA~1/R/R-31~1.1/etc"
R.home("modules")
# [1] "C:/PROGRA~1/R/R-31~1.1/modules/i386"
R.home("share")
# [1] "C:/PROGRA~1/R/R-31~1.1/share"