stream.converter field blank, trying to set up BBC Radio Streaming

[Thinbo]

Hi, Apologies I don't really know what I'm doing

I'm trying to set up an alternate way to stream BBC Radio on my Sonos system, since their recent format changes mean all live sporting commentaries are blanked due to rights restrictions. I'm following the following instructions: these instructions (http://minimstreamer.com/naim/bbcradio.html)

It was going smoothly until I got to step 9:
Check that the stream.converter field contains the value ffmpeg or avconv. If this field is blank, post to the MinimStreamer section of the MinimServer support forum for advice (see the Support page).

the steam.converter field is blank, so I am looking for some advice as to how to proceed.
I am doing this on my PC rather than a NAS/Server, running Win8.1 I've confirmed that everything is 64-bit (Windows, Java and Minimserver)

thanks in advance for any help