Its called command line rendering.

You can either call a file corm the command line so that nothings open and render it form there with the files render settings, if you open a command shell and type render -h you get all the info and the overide flags that you can set.

You can also write the instrustiuons in a notepad file save it as a .bat and then double click to set it off.

OR

The real lazy way is to set up the render settings in the file MR, FG, GI all that save it, locate the file, right click and click render. A command window should open any you can see the progress of the render