Rtools not being detected by R

Question

Update:

I've written a brief walkthrough guide to installing Rtools on windows.

Original:

I am trying to build an R package using RStudio on Windows 7. When I attempt to build the package via RStudio's Build panel I receive:

WARNING: Rtools is required to build R packages but is not currently installed. Please download and install the appropriate version of Rtools before proceeding:

http://cran.rstudio.com/bin/windows/Rtools/

Loading library(devtools) and running find_rtools(T) gives:

Scanning path...
ls : F:\Rtools\bin\ls.exe 
Scanning registry...
Found F:/Rtools for 3.1 
VERSION.txt
Rtools version 3.1.0.1936 
[1] TRUE

The Path variable is set as:

F:\Rtools\bin;F:\Rtools\gcc-4.6.3\bin;F:\Rtools\perl\bin;F:\Rtools\MinGW\bin;F:\Program Files\R\R-3.0.2\bin\x64;F:\Program Files (x86)\HTML Help Workshop;F:\Program Files\MiKTeX 2.9\miktex\bin\x64\;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Program Files\Common Files\Microsoft Shared\Windows Live;C:\Program Files (x86)\Common Files\Microsoft Shared\Windows Live;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\Windows Live\Shared;C:\Program Files\Microsoft Network Monitor 3\;F:\Program Files (x86)\QuickTime\QTSystem\

I've also restarted several times, yet the error persists. I'm a bit confused as to why this is occurring.

Output when R access system variable Path:

> Sys.getenv()['PATH']
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 PATH 
"F:\\Program Files\\R\\R-3.0.2\\bin\\x64;F:\\Rtools\\bin;F:\\Rtools\\gcc-4.6.3\\bin;F:\\Rtools\\perl\\bin;F:\\Rtools\\MinGW\\bin;F:\\Program Files\\R\\R-3.0.2\\bin\\x64;F:\\Program Files (x86)\\HTML Help Workshop;F:\\Program Files\\MiKTeX 2.9\\miktex\\bin\\x64\\;C:\\Program Files (x86)\\NVIDIA Corporation\\PhysX\\Common;C:\\Program Files\\Common Files\\Microsoft Shared\\Windows Live;C:\\Program Files (x86)\\Common Files\\Microsoft Shared\\Windows Live;C:\\Windows\\system32;C:\\Windows;C:\\Windows\\System32\\Wbem;C:\\Windows\\System32\\WindowsPowerShell\\v1.0\\;C:\\Program Files (x86)\\Windows Live\\Shared;C:\\Program Files\\Microsoft Network Monitor 3\\;F:\\Program Files (x86)\\QuickTime\\QTSystem\\" 

The R version I am using is: R version 3.0.2 (2013-09-25) -- "Frisbee Sailing."

The Rstudio Version I am using is: 0.97.551. When I check for updates, I'm told that this is the latest patch.

> Sys.which("ls.exe")
                   ls.exe 
"F:\\Rtools\\bin\\ls.exe" 
> Sys.which("gcc.exe")
gcc.exe 
     "" 

Answer 1

Turns out when I installed RTools I left out the R 2.15.x+ toolchain option in the installation, which lead to the gcc never being installed. Hopefully, this post will serve as a diagnostic guide if RStudio fails to register RTools.

Thank you everyone for your help.