Finally have the full solution for this. I bought a nice Yamaha external sound card which was set up for Vista. The drivers which came with it said that because Vista disables all sound recording it will not recognise the recording ports, that must be done in Vista. In fact the drivers didn't work properly but Yamaha have just released new drivers which do work.
On the Vista side, more confusion. As discussed on many Vista sites Microsoft decided to make the recording software inaccessible but advised sound equipment manufacturers on how to get this to work. None of the manufacturers have been able to understand MS's instructions.
I downloaded the latest Vista upgrades. Then was able to open the separate Realtek management interface in the Control Settings and demote the internal soundcard from being default. Only then could I right-click on the Sounds window's properties to show hidden icons and reveal the USB card and make them the default sound applications for playback and recording.
Trouble was, the new recording tab showed only that it worked, there was no sliding rule to adjust volume, so it was still too quiet.
More research - this has finally been addressed in Vista Service Pack 1. So I spent a day backing up my current config and then another few hours downloading and installing SP1.
At last the levels can be controlled and recordings can be made. If you want to record to your PC I suggest you stick with XP!
