R installation
From AWF-Wiki
Installation of R Project for Statistical Computing
Download the installer R-3.4.4-win.exe which conains a binary distribution of R-3.4.4 to run on Windows (including 64-bit version of Windows). Just run this for a Windows-style installer with standard user rights not as administrator. During setup it is better to change the default installation folder to another folder (e.g. to C:\OSGeo4W64\bin\apps\R\R-3.4.4) because write access to this folder is needed using the QGIS Processing Toolbox.
