JezPX73, welcome to the Seven Forums.
I have tried connecting the Inspire 5.1 decoder using a din cable and then into the laptop (via the headphone/spdif/line out socket), but I get no sound.
Did you remember to set the default playback device in the Windows playback properties to SPDIF/digital? If you left it set to speakers, that could be why you're not getting any sound. Also I assume this is what you used for the connection,
It is possible that the DIN connection will only work with Creative sound cards. If that is the case try it using the single connection from above for 2 channel audio, and then use either CMSS or Dobly Prologic to upmix it to 5.1.
You might even be able to get away with the coax connection using the same single cable as above from the laptop and one of these, For only $0.21 each when QTY 50+ purchased - RCA Plug to 3.5mm Mono Jack Adaptor - Gold Plated | 3.5mm <--> RCA Adapters
on the RCA coax jack on the bos.