Realtech is the name of an internal sound card.  Look in control pannel, 
sounds and audio devices.
The third property sheet is for audio settings.
I don't have a windows 7 machine in front of me, so this might be different.
Look for a check box that says "use only prefered sound drivers".  Checking 
this might force Jaws not to think their is another sound driver installed.
I am not sure if a USB source will over ride this setting or not.
Hopefully somebody here is running 7, and can clarify this idea.