the order that Origin find the R is:
Check the environment variable "R_HOME";
Check the registry(the value of InstallPath in HKEY_LOCAL_MACHINE\SOFTWARE\R-core\R);
Check the uninstall path(HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\R for Windows xx.yy.zz_is1);
Check ini file ORConfig.ini(show a dialog to choose a R program to launch, and save the path to ORConfig.ini) in the path of the directory designated for temporary files(%TEMP%\ORConfig.ini, the value of Location in RHome section).