Their is a great freeware program, if the http://www.jfwlite.com page is
still there. The program is quickmix quick audio mixer.
What it does, is to create a file with your current audio settings. You can
make multiple files, and then make a hotkey to one of them from your
desktop. That way, if you loose sound, press the hotkey and your
functioning audio settings will be returned. I use the program for
selecting different audio inputs and audio levels. Files like mike,
turntable, vcr, and web. The names tell you what they are for.