If you don't have a volume control software on your PC, or are not satisfied with the standard solution from Microsoft; want a Windows audio mixer with advanced features such as quick and easy volume tuning by using hot keys and mouse, saving and restoring all your audio settings just by one mouse click, scheduled volume adjusting, command line support and much more - try Power Mixer.
I don't understand others rating this so low. I think it's great. Really good value too!