Hi Richard,
You might want to give "QuickMix" (http://www.ptpart.co.uk/quickmix/) a try (current version is 1.06, it's freeware). It enables you to save and restore audio settings under windows (you can also adjust loudness by editing some hex values in the saved config file; send me a PM in case you need more information on this issue). This is what we use in our lab to have different fixed settings for different experiments.On my computer (Windows XP), all I have been able to find, even in the advanced settings, are scrollbars indicating the volume level. Is there any way to check/adjust numerical values of the volume setting?
Hope this helps, Andreas