Well all this talk has made me look more closely at my recording setting... Despite it saying it was a microphone on rear input, it is actually a virtual device with Anvsoft driver. It was /is part of Any Video converter software.
Doing a search for it led me to this site....
http://win.cutephp.com/t/anvsoft_virtual_sound_device/ Which I notice has a free virtual audio cable , I used to use a lot of virtual cables when I had quite a large midi system.
Also it has a free AV audio and sound recorder programme , that creates and records off of virtual devices from
http://win.cutephp.com/av_audio_and_sound_recorder_2850969/This might prove a good back up to use in odd one of cases.