I use Windows 7 which has a Microsoft High Definition audio device. All the necessary inputs and output connections are correct but I cannot play and listen to an audio signal from an external device; e.g. a tape deck or transcription record player. If I input signals from either into music programs on my computer they record as necessary and playback after recording is OK as is playing a cd from the computer player but I can't listen to music from the correctly connected and working external devices and drivers are correct and up to date. All else seems to work so what to do please.
You are saying you can record from external devices but if you want to listen to the input in real time from the same source, that doesn't seem to work ? I just wonder if one is supposed to be able to do that. If so it might be a driver issue, or maybe you need a particular application to do it.
Hope that gives some pointers as to where I'd look next, although someone more knowledgeable re PC audio things is sure to be along in a bit.
I think that what you are trying to do is not possible as your computer cannot output to the external devices. You may have to use a sound card which should connect to your external devices to deliver the output