Are there proper instructions for building R under windows?

Question

R

I need to rebuild R on Windows, ideally on gcc 4.9.x , but I started from far away and tried the build instructions offline at cran.r-project.org/doc/manuals/r-release/R-admin.h.. I tried all possible options to approach the assembly of
this case, even created a clean virtual machine with windows7, but I can't assemble it even if I follow the steps of the instructions.
If anyone has experience with assembling this thing, please respond, I need your help.