Install R package from source, without changing PATH (Windows) - windows

Question

I'm trying to install package rpart for R-2.14.0 on Windows 7, but I get the warning:
package ‘rpart’ is not available (for R version 2.14.0)
So I download the tar.gz file from the package page. I have installed Rtools but I disabled all the options, including the one that changes the PATH. Then I do the following:
> install.packages("C:/rpart_3.1-50.tar.gz", type="source")
Installing package(s) into ‘C:/Users/backupSam/Documents/R/win-library/2.14’
(as ‘lib’ is unspecified)
inferring 'repos = NULL' from the file name
* installing *source* package 'rpart' ...
** libs
*** arch - i386
ERROR: compilation failed for package 'rpart'
* removing 'C:/Users/backupSam/Documents/R/win-library/2.14/rpart'
* restoring previous 'C:/Users/backupSam/Documents/R/win-library/2.14/rpart'
Warning messages:
1: running command 'C:/PROGRA~1/R/R-214~1.0/bin/i386/R CMD INSTALL -l "C:/Users/backupSam/Documents/R/win-library/2.14" "C:/rpart_3.1-50.tar.gz"' had status 1
2: In install.packages("C:/rpart_3.1-50.tar.gz", type = "source") :
installation of package ‘C:/rpart_3.1-50.tar.gz’ had non-zero exit status
Any suggestions?

Answer 1

Since you have to set the PATH, but you're hesitant to do so because you're afraid you may hose something up, you can do it temporarily in your R session via:
pathRtools <- paste(c("c:\\Rtools\\bin",
"c:\\Rtools\\MinGW\\bin",
"c:\\MiKTeX\\miktex\\bin",
"c:\\R\\bin\\i386",
"c:\\windows",
"c:\\windows\\system32"), collapse=";")
Sys.setenv(PATH=paste(pathRtools,Sys.getenv("PATH"),sep=";"))