How To: Verify Rstudio is Using User Installed Rtools

How do I verify that Rstudio is using Rtools installed in my user profile?

1. Using RStudio > Console pane, enter 'Sys.which("make.exe") ' at the prompt. 

The resulting path string shows the location of your Rtools installation. Confirm it resides in your user profile and is writable so it can be used without administrative privileges.

Example for Rtools 4.5 under user TrumanT: "C:\\Users\\trumant\\rtools45\\usr\\bin\\make.exe"

2. (Optional: test Rtools linking using devtools package) 

     a. If not installed, install devtools in RStudio > Console:

          > install. Packages("devtools")

     b. Test devtools installation in RStudio > Console:

          > devtools::find_rtools()