Hi Mac. well, I've spent several hours looking at this, and am not sure I'm much wiser.

So far as I can see, Midi tracks essentially make "sound commands" which are not audio files. This requires a device (hardware or software?) of some sort to interpret the sound. This could be external or internal. Presumably I have such a device, because I can hear Midi sounds when using BiaB.
This device requires a driver, but the driver I have is not adequate.

It looks like ASIO drivers are the thing to have, so long as one's sound card supports them. I have downloaded ASIO4ALL, and it looks to have installed correctly.

Now the problem I have is that if I go inot BiaB audio settings and selct the ASIO driver, rather then the MME driver, I cant get any sound at all - not even on RT or RD ie non Midi. Ive tried restarting Win and BiaB, but no joy. I still get sound elsewhere in Win.

ANy ideas please?