This script is written in perl, and is cross platform compatible, i.e. works in Linux, Windows or any other OS that can run perl scripts.
Install ActiveState perl
Download the script from my Github: https://github.com/droidzone/subtitlegetter
Copy the context menu handler .cmd file to the approproiate location
Import the .reg file after modifying any paths in it.
Now you can right click any folder in explorer and download automatically subtitles for all files in the directory.