Another Rtools install page

Install Rtools.exe

Go https://cran.r-project.org/bin/windows/Rtools/

If you are using R 3.5, get Rtools35.exe

Once the installer is downloaded, run. Accept all of the defaults EXCEPT when the installer asks you about changing your path. It is critical that you pay attention to the installer and make sure the checkbox is indeed checked. The installation won't work if the box isn't checked.

Once the installer is finished, look in your c:\ drive to make sure you can see the c:\Rtools folder.

Once you have verified the c:\RTools\ folder, close down any open Rstudio windows and restart.

Check the PATH environment variable by typing Sys.getenv("PATH") in the R console. You will see the PATH printed to the console and you should see the two following locations registered in your path:

c:/Rtools/bin/ .

Once you have verified that the path is properly set, try running a mrgsolve model

library(mrgsolve)
mod <- mread("pk2", modlib())

mrgsim(mod)

If you are still getting compile error with status 127, set this environment variable in R

Sys.setenv(BINPREF = "c:/RTools/bin/")

This sets an additional environment variable, telling R what to use for the compile command.

Then try to test again:

library(mrgsolve)
mod <- mread("pk2", modlib())

mrgsim(mod)

If this still isn't working, report an issue here (requires a GitHub account): https://github.com/metrumresearchgroup/mrgsolve/issues