Note that if you install the new JRiver WDM as the default audio device in "Windows>Sound" then you would select your actual sound device (like "RealteK High Definition Audio", or whatever you computer sound card is) in the JRiver audio setup. Then you must have JRiver running all the time to get sound in other non-JRiver programs.
If you don't want all the sound always going through JRiver program, you would not use the JRiver WDM driver as your "default" sound device in Windows>Sound.